TRANSACTIONS OF WAGNER 

 1062 



TERTIARY FAUNA OF FLORIDA 



> Cooperella Carpenter, Rep. Brit. Assoc. for 1863, pp. 6n, 639, 1864; Proc. Cal. Acad. 



Sci., iii., p. 208, 1866. 



> Oedalina Carpenter, Proc. Cal. Acad. Sci., iii., p. 208, 1866 (as a substitute for Ocdalia 



Cpr., 1864; not Meig., 1830). 



In 1864 Carpenter described the type of this genus and the genus itself in 

 three lines as two species of two subgenera, both of which were regarded as 

 new, and the types of which are in the National Museum. One of the names 

 used was preoccupied and, as both applied to the same species, the second 

 name must be adopted. A year later Carpenter gave full diagnoses of genus 

 and species under the preoccupied name, and in 1866, still regarding them 

 as distinct, he gave a full diagnosis for the supposed subgenus and substi- 

 tuted Oedalina for the preoccupied Ocdalia. The supposed subgeneric dif- 

 ference was based on the assumed (but not real) absence of an internal liga- 

 ment in the type and its less bifid cardinal teeth. The latter character is 

 shown by material in the collection to differ among adult individuals and 

 probably in the same individual at different ages. The specific name under 

 which the species was first fully described is here adopted for the type. The 

 characters of the genus are as follows : 



Shell small, thin, smooth, or concentrically striate or undulate, equivalve, 

 nearly equilateral, with entire margins ; ligament long, feeble, profuse, amphi- 

 cletic ; resilium short, stout, opisthodetic, immersed behind the cardinals on an 

 oblique thickening of the hinge-plate, not excavated to form a pit or produced 

 into a chondrophore ; hinge-plate narrow, carrying two right and three left 

 subumbonal divaricating short cardinal teeth, of which the left central tooth 

 is always, and the others frequently, bifid ; laterals none ; muscular impres- 

 sions small, oval ; pallial line narrow with an ample sinus ; siphons long, 

 slender, separate, the branchial fringed at its orifice ; mantle margins simple, 

 free, for about half the length of the shell, gills rather small, free, with direct 

 and reflected inner and outer laminae, palpi very small, foot compressed, quad- 

 rate, without any byssal groove or obvious gland. 



I give the anatomical characteristics from the typical species because they 

 have not been recorded anywhere and have an important bearing on the 

 relationship of the genus. Excepting the large sinus the shell strongly recalls 

 Psathura Deshayes. 



The type Cooperella subdiaphana (-\-scintillifonnis) Cpr. is not uncom- 

 mon, living on the Pacific coast between Vancouver Island, Monterey, and 

 Todos Santos Bay, but owing to the extreme fragility of the shell is difficult 

 to preserve intact. It was with peculiar interest, therefore, that I noted the 



