This essay was subsequently published as:
Dillon, R.T., Jr. (2023b) A House Divided.
Pp 61 – 71 in The Freshwater Gastropods of North America Volume 6,
Yankees at The Gap, and Other Essays.
FWGNA Project, Charleston, SC.
By the spring of 1862, America had reached a point of
crisis. Isaac Lea had run out of names
for pleurocerid snails.
Lea led his 1863 description of Goniobasis pybasii [11] with “shell folded, very much drawn out,” and went to unusual lengths comparing it to four other species previously described: “reminds one of laqueata (Say),” “allied to deshaysiana but more slender [12],” “very much like grata (Anthony) [13],” and “differs from lyonii by not being striate [14].” He did not distinguish pybasii from perstriata, nor indeed from any of his East Tennessee species, troostiana or any of the synonyms we reviewed in January. Lea gave the habitat of Goniobasis pybasii as “Tuscumbia, Alabama, B. Pybas [15].”
Between 1834 and 1861 Lea had described 184 species in the
genus Melania, which he now wrote had become “so enormously extended as almost
to prevent the possibility of finding suitable names for its species.” So in April of 1862 Lea [1] proposed to split
a large subset of Melania bearing shells with “auger-shaped” apertures into a new
genus Trypanostoma. And in May [2] he
proposed to split another large subset bearing shells with “subrhomboidal”
apertures into a second new genus, Goniobasis.
Lea then went on to describe 242 new pleurocerid species in
18 months, as though the pressure in some vast balloon of Latinate adjectives
had suddenly been exploded by nomenclatorial pin prick. The splatter included spinella which we
reviewed in January [3] and the aterina / porrecta / vittatella / cumberlandensis
clot we featured way back in August [3], sent to Lea by Captain Lyon from way
down yonder in Cumberland Gap. Also
detonated onto the pages of learned journals in 1862/63 were a tremendous
variety of additional nomina assigned to pleurocerid populations from
throughout the Tennessee/Cumberland region, including Goniobasis gabbiana,
which immediately arced into oblivion, only to be called back on this blog in
2016 [4].
Lea’s genus Trypanostoma never caught on. George Tryon [5] considered it
“unquestionably” a junior synonym of Rafinesque’s Pleurocera [6], as did
Goodrich [7] and Burch [8]. But Lea’s
genus Goniobasis was accepted by both Tryon and Goodrich as describing a “natural”
group, hanging on until the 1980s, when Burch resurrected the zombie taxon,
Elimia, to replace it.
We now understand, of course, that the distinction made by
Lea in 1862 was illusory. There is
no evolutionary difference between
Trypanostoma, Pleurocera, Goniobasis or Elimia whatsoever [9]. The tragic rift that tore the pleurocerid
fauna apart in 1862, setting brother against brother, would not be healed for
150 years.
Nevertheless, in 1873 George Tryon, almost certainly in
direct consultation with Isaac Lea himself, divided all 184 species that Lea
had described prior to the Trypanostoma/Goniobasis crisis of 1862 into
either Pleurocera or Goniobasis. In
general, the larger and more heavily-shelled nomina went into the former genus
and the more lightly-shelled species into the latter. During that process, all five of the
previously-described slender, striate East Tennessee species we discussed in
January [3] were allocated to Goniobasis: troostiana (Lea, 1838), teres (Lea,
1841), strigosa (Lea, 1841), striatula (Lea 1841) and arachnoidea (Anthony
1854). As well as the perstriata Lea
described from North Alabama in 1852.
So last month we reviewed the situation with Melania (now
Goniobasis) perstriata, suggesting that the Huntsville-area populations
described by Lea using that particular sobriquet might best be understood as a
plicate subspecies of the troostiana population he described from East
Tennessee way back in 1838. We also
hinted that quite a few additional names for similar populations inhabiting
similar waters of North Alabama might have been described in the aftermath
of the 1862 unpleasantness [10]. Among these were pybasii (1862), paupercula
(1862), crispa (1862) and decampii (1866).
 |
| Pleurocera troostiana populations, Note [22] and map below. |
Lea led his 1863 description of Goniobasis pybasii [11] with “shell folded, very much drawn out,” and went to unusual lengths comparing it to four other species previously described: “reminds one of laqueata (Say),” “allied to deshaysiana but more slender [12],” “very much like grata (Anthony) [13],” and “differs from lyonii by not being striate [14].” He did not distinguish pybasii from perstriata, nor indeed from any of his East Tennessee species, troostiana or any of the synonyms we reviewed in January. Lea gave the habitat of Goniobasis pybasii as “Tuscumbia, Alabama, B. Pybas [15].”
Tryon [5] passed pybasii along verbatim. Goodrich opened his 1930 treatment of G.
pybasii [17] with the observation that “this species does not seem to have been
collected in recent years.” He did,
however, examine nine shells (bearing poor data) then held by the Alabama
museum, writing “The chief characteristic of the species is that, unlike the
other plicate Goniobases of the region, it lacks the granulate spire and the
usual revolving raised lines.” He went
on to broaden its range to “springs and streams of North Alabama.” Burch [8] passed Elimia pybasii along on his
page 140, unfigured.
So on March 12, after my tour of lovely Madison County,
Alabama, I struck out across the rolling hills and lush farmlands toward
Tuscumbia, the home of Hellen Keller, Annie Sullivan, and the first railroad on
the American frontier [18]. And over the
course of several days following, I was able to inventory, lightly but
completely, the freshwater gastropod fauna inhabiting the springs and small
streams of North Alabama.
And it materializes that pleurocerid populations bearing
“shells folded, very much drawn out” that match Lea’s figure of 1863 are today
widespread in the springs and small streams south of Tuscumbia. And as a type locality for Goniobasis
pybasii, I hasten to nominate what may be my favorite freshwater gastropod
sampling site ever, the small spring and spring run at the foot of the
Rattlesnake Saloon (Q).
 |
| My favorite sampling site, ever. |
By great good fortune, the hour was getting on toward
quitting time on a Wednesday evening when I pulled my pickup into the ample
parking lot of the Rattlesnake Saloon, about 2 miles south of Tuscumbia. The public establishment is located a brief
stroll through verdant pastureland and a steep descent under a massive rock
overhang about 20 – 30 yards above Newsom Springs. Beer and pleurocerids on a warm Alabama
evening in mid-March? I cannot remember
ever enjoying anything I have called “work” more than this. See the example shell marked (Q) above.
Lea described Goniobasis paupercula [11] in the same 1863
article as pybasii, 11 pages later, giving the habitat simply as “North
Alabama, Prof. Tuomey [19].” His
description of the “subcylindrical” shell mentions whorls “folded above and
striate at the apex.” But in his remarks, he confessed that he had “not a
single one with an entirely perfect apex, being usually decollate at the second
whorl from the base.” In contrast to
pybasii, Lea did not compare paupercula to any other pleurocerid previously
described – not to perstriata or anything else – implying, I suppose, that
something in his description made paupercula self-evidently unique. Possibly the decollation? In any case, Tryon passed paupercula along
uncritically.
Goodrich (1930) reported observations on seven populations
of paupercula collected by H. H. Smith from small streams in Lauderdale and
Franklin Counties, Alabama. Goodrich’s
notes on shell morphology expanded those of Lea considerably, especially with
respect to variation in shell sculpture.
Burch [8] picked up the species from Goodrich (1940) and passed it along
(with Tryon’s redraft of Lea’s original figure) on his page 140, giving the
range simply as “creeks of Northern Alabama.”
 |
| Juvenile, 9.2 mm |
My surveys through Lauderdale and Franklin Counties this
March did not yield any pleurocerid populations bearing decollate shells. But I did stumble upon a population bearing
shells very nearly identical to Lea’s 1863 description and figure in Lipscomb
Spring, south of Huntsville, on the opposite side of the Tennessee River
(R). The figure above shows an adult
shell, the figure at left a juvenile, suggesting that Lea’s speculation about
striae around the apex was correct.
Although it seems likely that Lea meant to publish a brief, Latinate description of Goniobasis
decampii in 1863, the actual description did not appear until 1866 [20]. The shell, he reported, was
“plicate, striate below, greatly attenuated, thin.” Lea gave the habitat as “Huntsville, Alabama;
Wm. H. DeCamp, MD, surgeon United States Army [21].”
To quote Goodrich (1930) verbatim:
“This mollusk is G. perstriata in all essentials save its nearly cylindrical shape. Quite slender specimens of perstriata have been taken in Big Spring Creek at Huntsville… It is possible that the original collector, Dr. DeCamp, had visited some spring or creek in the vicinity of Huntsville containing these shells, and that the locality has not since been examined. A ‘pure culture’ of decampii would warrant, of course, its definite recognition.”
In my week of sampling springs and streams around North
Alabama I did not find a single individual pleurocerid bearing a shell as
“greatly attenuated, thin” as Lea’s figure suggests, much less a “pure culture.”
Goodrich’s speculation seems quite plausible to me – that the single
shell sent Lea by Dr. DeCamp was subsampled from the perstriata population of
Big Spring, Huntsville, subsequently much impacted by development.
The biological and morphological considerations reviewed above
combine to suggest to me that all three of these nominal species, pybasii (Lea
1862), paupercula (Lea 1862), and decampii (Lea 1866), are junior synonyms of
Pleurocera troostiana perstriata (Lea 1853).
All three of these nineteenth-century taxa were defined entirely by
their shell morphology. And the shell
morphology demonstrated by the example populations we have identified this
month rests easily within the variance of the Huntsville-area P. troostiana
perstriata populations we documented last month.
 |
| North Alabama. See footnote [22] for locality data. |
But regarding crispa (Lea 1862). Lea described Goniobasis crispa from
“Florence, Alabama; Rev. G. White” in the same 1863 paper as pybasii and
paupercula, two pages after the latter [11].
Goodrich neglected it in his 1930 work but brought crispa back as a
subspecies of Goniobasis perstriata in 1940 [7]. No, Goniobasis crispa is not a subspecies of
perstriata, nor is it a synonym of troostiana, nor is it related to any other
species we have treated this month, or at any time in recent memory. Goniobasis crispa (Lea 1862) is entirely
different. And to quote my favorite
Alabaman, “That’s all I’ve got to say about that.”
But I will say two more things about two other gastropod
populations and close with one rhetorical question. The first thing I will say is that the
tributaries of the Elk River in North Alabama are inhabited by pleurocerids
bearing slender, lightly-costate shells no different from any of the other
Pleurocera troostiana perstriata populations we have reviewed in the last
couple months. See the example shell
from Mechanic Branch at Sim Corder Mill (S) figured way up above.
And the second thing is that if one samples up the main Elk
River just a short way into Tennessee, one begins to discover populations of
pleurocerids bearing slender, high-spired shells elaborately ornamented with
both strong striae and dramatic costae down the entire length of their shells,
from apex to lip. See the example from the Elk River at Kelso (G) above.
What is the situation with Pleurocera troostiana in Middle
Tennessee? Stay tuned.
Notes:
[1] Lea, Isaac. (1862) Description of a New Genus
(Trypanostoma), of the Family Melanidae, and of forty-five New Species. Proc. Acad. Sci.,
Phila., xiv, pp. 161 - 175.
[2] Lea, Isaac. (1862) Description of a new genus
(Goniobasis) of the Family Melanidae and eighty-two new species. Proc. Acad. Nat. Sci., Phila.,
xiv, pp. 262-272.
[3] Here’s my entire series on Pleurocera troostiana:
- CPP Diary: Yankees at The Gap [4Aug19]
- On the trail of Professor Troost [6Dec19]
- The many faces of Professor Troost [7Jan20]
- Huntsville Hunt [15Apr20]
- The cryptic Pleurocera of Maryville [13Sept16]
- The fat simplex of Maryville matches type [14Oct16]
- One Goodrich missed: the skinny simplex of Maryville is Pleurocera gabbiana [14Nov16]
[6] Tryon turned out to be quite wrong here. The question of whether Lea’s Trypanostoma
might indeed be a junior synonym of Rafinesque’s Pleurocera was swept up into
one of the longest-running feuds in American Malacology. See:
- Joe Morrison and the Great Pleurocera Controversy [10Nov10]
[8] This is a difficult work to cite. J. B. Burch's North American Freshwater
Snails was published in three different ways.
It was initially commissioned as an identification manual by the US EPA
and published by the agency in 1982. It
was also serially published in the journal Walkerana (1980, 1982, 1988) and
finally as stand-alone volume in 1989 (Malacological Publications, Hamburg,
MI).
[9] Dillon, R. T., Jr. (2011) Robust shell phenotype is a
local response to stream size in the genus Pleurocera (Rafinesque, 1818). Malacologia
53: 265-277 [PDF]. For more, see:
- Goodbye Goniobasis, Farewell Elimia [23Mar11]
[11] Lea described paupercula, pybasii and crispa in brief,
Latinate form in his 1862 PANSP paper cited at note [2]. They were figured and described more
completely in English the next year, in:
Lea, Isaac (1863) New Melanidae of the United States. Journal of the Academy of Natural Sciences of
Philadelphia 5: 217 – 356.
[12] Lea’s deshaysiana of 1841/42 (habitat “Tennessee”) was
synonymized under laqueata (Say1829) by Goodrich [7, 16].
[13] Anthony’s 1860 grata (habitat: “Alabama”) has been
buried by the sands of time. Rest in
peace.
[14] Put a bookmark here.
We will return to the Goniobasis lyonii populations of Kentucky in a
couple months.
[15] In the original (10May20) version of this blog post, I footnoted here, "About the life of Mr. Pybas I have found nothing." In September, however, I was pleased to receive an email from Ms. Robin Gaither, a great, great granddaughter of Benjamin Pybas, whose dates I now know to be 1808 - 1883. Ms. Gaither shared that Grandpa Ben was a cabinet maker and coffin maker / undertaker in Tuscumbia. He was also an early member of the AAAS, and submitted several mathematical papers to the AAAS Proceedings of 1866, styling himself "Professor." Have you ever heard the Guy Lombardo standard, "Stars Fell on Alabama?" That song was inspired by a dramatic Leonid meteor storm in November of 1833. Grandpa Ben found a star and sent it to the Smithsonian [16].
[16] Actually, the Smithsonian wasn't founded until 1846. I googled around and found a paper contributed to the Sheffield Laboratory of Yale College reporting a "meteoric stone" which fell 16 miles SE of Tuscumbia in 1868 being sent to Yale by Mr. Benjamin Pybas. But I like the "Stars Fell on Alabama" story more, so that's what I intend to pass along, regardless.
[17] Goodrich, C. (1930)
Goniobases of the vicinity of Muscle Shoals. Occasional Papers of the Museum of Zoology,
University of Michigan 209: 1 – 25.
[18] In 1834 local merchants completed a railroad from
Decatur to Tuscumbia to bypass the 43-mile Muscle Shoals of the Tennessee
River. This line was incorporated into
the Memphis & Charleston Railroad in 1850, ultimately becoming the first
connection between Alabama and The East.
Cotton was, of course, the primary motivation for the construction of
these commercial arteries. The conduct
of freshwater gastropods to Philadelphia was apparently an afterthought.
[19] Michael Tuomey (1805 – 1857), professor of geology at
the University of Alabama, appointed first state geologist of Alabama in 1848,
working out of Tuscaloosa, travelling broadly.
[20] 1866. Lea, Isaac. New
Unionidae, Melanidae, etc. chiefly of the United States. Journal of the Academy of Natural Sciences of
Philadelphia (New Series) 6: 113 – 187.
[21] Dr. William H. DeCamp (1825 – 1898), originally from
New York, removed to Grand Rapids in 1854, served as a surgeon in the First
Michigan Engineers and Mechanics Regiment 1861 – 64. He resumed practice in Grand Rapids and was
ultimately elected to the presidency of the Michigan State Medical Society.
[22] Pleurocera troostiana populations referenced in this
essay:
- Q = Newsom Springs at the Rattlesnake Saloon. 34.6481, -87.9076
- R = Lipscomb Spring. 34.5241, -86.6013
- S = Mechanic Branch at Sim Corder Mill. 34.9364, -87.1314
- G = Elk River 2 km N of Kelso. 35.1395, -86.4484