24© JOURNAL OF CONCHOLOGY, VOL. 10, NO. 8, OCIOBER, I902. 



less full, less elongated," the concentric strise " coarser and more dis- 

 tant" and in its " uniform white color." The figure, magnified nine 

 times, is bad. The hinge is incomprehensible, the concentric sculp- 

 ture is represented as very fine. Nothing is said about a lunule or 

 the number of teeth, though the figure looks as if the draughtsman 

 had intended to represent lateral teeth. 



The specimens, supposed to be of this form, which I have seen, are 

 all less flat and more inflated than the Massachusetts variety, instead 

 of less so, and therefore cannot be typical. 



In 1869, Perkins,^ on the ground that the British Association rules 

 forbid the use of a specific name for generic purposes, rejects Gemma 

 Deshayes and substitutes Tottenia, which by a typographical error is 

 printed Totteniana in his text, though corrected in the errata. He 

 calls the species collected in the vicinity of New Haven Tottenia 

 gemma. He adds to our knowledge of the animal the important in- 

 formation that it is viviparous, producing over thirty young to the 

 individual mother. The young were well formed in January. 



In 1870, Binney,^ under Gemma, gives a translation of Deshayes' 

 Latin generic diagnosis and notes (from information furnished by 

 Stimpson) that the animal has the siphons connate, the anal one 

 valvular, the lower one longer and fringed, and the "foot semilunar." 

 Under Gemma gemma the Massachusetts form is figured, but Gould's 

 text of 1841 which does not harmonize with the Deshayesian diagnosis 

 is retained unchanged. G. viatihattanensis is treated as a distinct 

 species. Prime's figure and remarks being practically reproduced. 



In Tryon,^ the genus Gemma is adopted with the Deshayesian 

 diagnosis, and no new information is added. 



By Prof. Verrill,^ the name Tottenia is adopted for the genus. T. 

 gemma is stated to extend from South Carolina to Labrador, and 

 T. man/iattanensis, regarded as questionably distinct, from North 

 Carolina to Vineyard Sound. An allied species T. sphcericd {Cytkerea 

 sphcerica, H. C. Lea)'' is stated to exist in the Miocene of Virginia." 

 It is noted that some specimens of T. man/iattanensis are purplish and 

 others straw color, and that its specific distinctness is doubtful. 



It will be seen from the preceding historical review that a complete 

 and correct description of this little shell is nowhere to be found and 

 that all accounts hitherto published are more or less deficient even if 

 untinctured with actual error. 



1 Proc. Boston Soc. Nat. Hist., vol. 13, p. 148. 



2 Gould's " Invertebrata of Massachusetts," pp. 137-138. 



3 "' American Marine Conchology," 1S73. 



4 " Report on the Invertebrate Animals of Vineyard Sound," Re^. U. S. Fish Comyti. for 1871-2, 

 p. 683, 1S73. 



5 Trans. Amer. Phil. Soc, series 2, vol. 9, p. 15, pi. 34, fig. 22, 1843. 



6 This proves to be a small species of Diplodonta. 



