Dr. Rob Dillon, Coordinator

Thursday, December 3, 2020

The Emperor Speaks

Editor’s Note – This essay was subsequently published as: Dillon, R.T., Jr. (2023c)  The Emperor Speaks.  Pp 253 – 260 in The Freshwater Gastropods of North America Volume 7, Collected in Turn One, and Other EssaysFWGNA Project, Charleston, SC.

I will begin my essay this month confessing an error that I committed in the late summer of 2018, as relayed to this group two months ago.  Here is a direct quote from my 5Oct20 essay on the “Flat-topped Helisoma of the Everglades”

“So, reading Wetherby’s description in the calm of my office here one sunny morning in Charleston a couple years ago, I was stricken with the impression that the type locality of Helisoma duryi might could use a bit of narrowing-down.  And I swiveled my chair and pulled my well-thumbed copy of F. C. Baker’s (1945) “The Molluscan Family Planorbidae” off the bookshelf.”

That was lazy of me.  I should have consulted Baker's mentor, the Elderly Emperor [1] Dr. Henry A. Pilsbry (1862 - 1957).

His regal ghost still flickered, dimly, through the hollow corridors of the mollusk collection at the Academy of Natural Sciences during my years as a graduate student in Philadelphia.  When I arrived at that venerable institution in the summer of 1977, the first stop on my first tour was the “Pilsbry Chaos,” a pile of boxes, papers, and shells through which curatorial assistants were still laboring, 20 years after the great man’s death. 

From H. B. Baker [2]
He was born on a small farm near Iowa City and seems to have developed his interest in land and freshwater shells at the nearby University, from whence he was awarded his B.Sc. in 1882.  Pilsbry then became a newspaper man, briefly, as was his contemporary Calvin Goodrich [3], moving to New York City as a proofreader in 1887.

He rocketed to malacological stardom almost immediately thereafter, at the age of 25.  On Thanksgiving Day of 1887, Pilsbry was invited to Philadelphia by George W. Tryon [4], who offered him a job as his assistant.  When Tryon died suddenly in February of 1888, Pilsbry inherited Tryon’s position as Conservator the Conchological Section, and Editor of the Manual of Conchology.  Pilsbry sat behind that high desk at the ANSP for 70 years, until they carried him out on a plank [5].

In 1889 he founded “The Nautilus,” the Volume 70 galleys of which were on the cluttered desk around which his plank was wedged.  Frank Collins Baker also came to Philadelphia to work with Pilsbry in 1889, and left the next year profoundly affected [6].  In 1890 Pilsbry organized the American Association of Conchologists, the first of several precursors to the American Malacological Union, of which he was elected first president.  In 1899 he was awarded a doctorate of science by his alma mater, the University of Iowa, the first of three doctorates he was ultimately to receive [7].

Pilsbry’s primary interest was in the North American land snails.  H.B. Baker characterized his (1895) “Guide to the Study of Helices” as “the most brilliantly original, iconoclastic book that ever has been written about the subject.”  Of land snails.  His four-volume “Land Mollusca of North America” (1939 – 1948) is the alpha of the American terrestrial gastropod fauna even unto the present day and may ultimately (I fear) prove to be the omega as well.

But the Elderly Emperor was widely published in freshwater, marine, and fossil malacology as well, from all over the world.  No one can count the sum of his works.  His biographers wrote, “an estimate between 3,000 and 4,000 possibly might cover the number of published articles that flowed from his facile pen.” Paging through the Burch canon [8], I count 57 species or subspecies of North American freshwater gastropods described by Pilsbry surviving even unto 1980, plus eight Pilsbry genera and three Pilsbry subgenera, in eight families.  Accepting Burch’s estimate of approximately 500 species, Pilsbry may be credited with describing over 10% of our freshwater gastropod fauna.  Not bad for a secondary interest.

So early in his career Pilsbry began taking regular vacations to Florida [10].  And in 1934 he published a large and wide-ranging paper in the Proceedings of the ANSP entitled “Review of the Planorbidae of Florida, with notes on other members of the family [11].”  The first 17 pages of that work were subtitled “I. The Large Planorbes of Florida,” which since not followed by a second section subtitled “The Small Planorbes of Florida,” turns out to have been what he meant by “The Planorbidae of Florida” in his main title, screw all those little ones [12].  The second 20 pages of Pilsbry’s 1934 paper were subtitled “Notes on Other Planorbidae,” which turned out to be an ambitious review of planorbid systematics across The Americas, with descriptions of a bunch of new species from three continents.  He described his new genus Australorbis about halfway through that second section, assigning Say’s (1818) glabratus to it, not helping [13].

Paratype lot of H. duryi in the UMMZ [9]

But it is the first half of Pilsbry’s 1934 paper that has brought him to our attention this month.  He began with Helisoma trivolvis, which (of course) is widespread throughout North America, which he allocated to the Dall subgenus Pierosoma.  He then undertook to describe a new subgenus, Seminolina, with Helisoma scalare (Jay 1839) as the type [14].  He also assigned to his new Seminolina two fossil species of Dall (conanti and disstoni) and “the Helisoma duryi complex.”  In the duryi complex he recognized, in addition to Wetherby’s typical subspecies of 1879, intercalare (Pilsbry 1887), preglabratum (Marshall 1926), and three new subspecies: seminole, normale, and eudiscus.  We touched briefly upon all this taxonomic churn back in October.  Sorry to bring it up again.

And regarding the type locality of Helisoma duryi, Pilsbry wrote: “Wetherby’s locality “Everglades of Florida” was vague and doubtless inexact.  I am informed by Mr. Ralph Dury [15] that in the trip of 1874 his father visited places along the coast of Volusia County – Tomoka River, Port Orange, Daytona, Halifax River […] It seems likely therefore that H. duryi was found somewhere along the eastern border of Volusia County.

D’oh!  Back in 2018, with F. C. Baker’s 1945 monograph open in my lap [16], I had convinced myself that a good typical (if not necessarily type) locality to sample H. duryi might be located on the Tamiami Trail at the 40-mile bend.  That is what sent me dodging airboats way down in The Everglades in October of 2018 [17], and that is why I had such high hopes for Cindy Norton’s 2019 breeding experiments [18].  In retrospect, I should have consulted The Elderly Emperor first.

In my own defense, here is the verbatim quote from Wetherby: “This shell was given me several years ago, by Mr. Charles Dury, who brought it from the Everglades of Florida.  It was also among the shells received from the Miami country.”  Volusia County is not in The Everglades, even under the most expansive modern definition of that term.  And Volusia is 250 miles north of Miami, and always has been.

Excuse logged.  Now go back to Florida, Dillon, and do your job right.

Digging into the Pilsbry paper further, it materializes that The Elderly Emperor examined Wetherby’s actual type lot, which Bryant Walker got hold of somehow, which sits in the UMMZ collection to this day.  That set of shells comprises a holotype (UMMZ 83501) and nine paratypes (UMMZ 83502) as figured above.  Pilsbry measured and figured four of the ten, including the holotype, which is where I got “19.5 mm” for footnote [3] of my October post.  And if you can believe it, Pilsbry split one of the shells out of Wetherby’s type lot of Helisoma duryi duryi into his own newly-described Helisoma duryi seminole.  See figure #4 in the Pilsbry montage below.

Wetherby’s type lot. #2 = holotype, #4 = H. d. seminole

Now would be an opportune time, I suppose, to make explicit what has, to this point in my essay, been implicit.  Henry Pilsbry was innocent of the Modern Synthesis.  The only species concept of which he was aware was the nineteenth-century “organism or group of organisms recognized as distinct by a competent taxonomist.”  Which Pilsbry, without question, was.  So, if His Imperial Majesty recognized a species, then it was a species, by definition.

And exactly the same for subspecies.  Under today’s modern synthesis of evolutionary thought, we define subspecies as “populations of the same species in different geographic locations, with one or more distinguishing traits [19].”  Pilsbry never considered that “different geographic locations” thing.  Subspecies were what he recognized as subspecies, just the same as species were what he recognized as species, only with less of whatever that species juice might be.

So although Pilsbry examined the type lot in Bryant Walker’s collection, it materializes that he never had any fresh Helisoma duryi duryi from anywhere in Volusia County in front of him.  Nor did his protégé Baker.  The type locality remained only slightly less mysterious to The Elderly Emperor than to me, reading his words in the calm of my office a couple months ago.

Volusia County is today home to approximately a half-million residents, 122 motels, 5 Walmart Supercenters, and the World Center of Racing.  Next month, we race off to Daytona!


[1] R. Tucker Abbott (1958) coined that sobriquet on page 103 of his contribution to the Pilsbry festschrift: "From the Pilsbry Chair of Malacology."  Nautilus 71: 100 – 103.

[2] I have gleaned most of the biographical details relayed here from Baker, H.B. (1958) Henry Augustus Pilsbry 1862 – 1957.  Nautilus 71: 73 – 83.

[3] Calvin Goodrich (1874 - 1954) was an early-modern malacologist, Pilsbry the paragon of the late pre-modern.  For more, see:

  • The Legacy of Calvin Goodrich [23Jan07]

[4]  We explored the relationship between George Tryon (1838 - 1888) and his immediate predecessor at the ANSP in:

  • Isaac Lea Drives Me Nuts [5Nov19]

[5] Not really, but darn close.  He suffered a heart attack at his desk in September of 1957 and died in his sleep in October.

[6] For a bit of background on my malacological hero, see:

  • The Legacy of Frank Collins Baker [20Nov06]

We will hear much more about the relationship between Baker and Pilsbry in coming months.

[7]  Pilsbry was ultimately awarded doctorates of science by the University of Iowa (1899), the University of Pennsylvania (1940), and Temple University (1941).

[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] We thank Taehwan Lee of the University of Michigan Museum of Zoology for braving the perils of the worldwide Coronavirus panic to assemble and photograph for us the lovely montage of H. duryi paratype lot 83502 reproduced above.

[10] Here’s a quote from T. L. McGinty (Nautilus 71: 97 – 100):  “Early in 1937, Dr. Pilsbry secured a cottage in Lantana, Florida, and each succeeding winter visit to his Florida home brought the Doctor new friends.”

[11] Pilsbry, H. A. (1934)  Review of the Planorbidae of Florida, with notes on other members of the family.  Proceedings of the Academy of Natural Sciences of Philadelphia 86: 29 – 66.

[12] Helisoma duryi, you may recall from my essay of October, was originally described by Wetherby (1879) as neither large nor small, but rather “medium-sized.”  Pilsbry (1934) folded the medium-sized planorbes in with the large.  I suppose we, the students who follow in the great man’s footsteps, should be grateful.

[13] Here’s a direct quote from H. B. Baker’s Pilsbry obituary [2]:

“Very rarely, when in a Puckish mood, did he (Pilsbry) wield his prestige to establish dubious cognomens; thus he argued against the use of Mesomphix instead of Haplotrema, but contrarily replace Planorbina guadaloupensis by (Biomphalaria) Australorbis glabrata (1934).”

I don’t know what that means, but it sounds important, so feel obligated to pass it along.

[14] John Clarkson Jay (1839) spelled the species name “scalaris” to agree in gender with the feminine Paludina.  Pilsbry re-spelled it scalare when he moved the specific nomen under the neuter noun-construct Helisoma in 1934.  Thanks to Harry Lee for the insight.

[15] We tipped our hat to Mr. Charles Dury in October footnote [4].  His son Ralph E. Dury (1899 – 1984) was Director of the Cincinnati Museum of Natural History for almost 60 years.

[16] Baker, F.C. (1945) The Molluscan Family Planorbidae. Urbana: University of Illinois Press. 530 pp.

[17] If you haven’t read it already, you might be entertained by:

  • The Flat-topped Helisoma of The Everglades [5Oct20]

[18] And as long as you’re reviewing my previous posts, you might as well bring yourself up to date:

  • Foolish Things With Helisoma duryi [9Nov20]

[19] To refresh your memory on the definition of the word “subspecies” as adopted by the FWGNA Project, see:

  • What Is A Subspecies? [4Feb14]
  • What Subspecies Are Not [5Mar14]