TRANSACTIONS OF WAGNER 



TERTIARY KAUNA Ol ; FLORIDA 



to and nearly parallel with the cardinal margin ; the auricular crura are 

 present, but there are no lirae. The margin of the valves is entire. The 

 colors are variegated and bright, recalling those of some deep-water species. 

 The form of the shell is nearly orbicular, moderately convex, and the height 

 and width of the disk is about an inch (twenty-five millimetres) in the largest 

 valves I have seen. It is supposed to come from the west coast of Africa. 

 The characteristics which separate this type from the deep-water forms for 

 which Verrill has proposed the name Cyclopcctcn are the direct result of the 

 environment, producing a thinner and less calcareous shell, more delicate 

 sculpture, and, as a rule, paler coloration. Those species of Cyclopcctcn which 

 range from comparatively shallow to very deep water, like P. alaskcnsis Dall, 

 have, in the shallow-water specimens, the margin of the right valve solid, 

 meeting the left valve evenly ; while those from very deep water have it less 

 calcified and consequently flexible. Otherwise the shells do not differ at all, 

 and the character not being of specific rank, it would seem is hardly available 

 for subgcneric distinctions. Cainptoncctcs and its synonyme, Eburneopecten 

 Conrad, are simply unribbed species of this group. 



Pecten (Pseudamusium) calvatus Morton. 

 Pccten calvatus Morton, Syn. Org. Rem., p. 58, pi. x., fig. 3, 1834. 



Original locality Eutaw Springs, South Carolina, Conrad ; also in the 

 Jacksonian of Alabama and at Hatchetigbee Bluff in the Chickasawan, Burns. 



There are two extremely similar species of Pscudciiniisiuin in the southern 

 Eocene ; both are smooth except for Camptonectes striation, both are nearly 

 orbicular when adult and more ovoid when young, both have the byssal ear 

 more or less radiated. They have been more or less confused, and the original 

 type of calvatus appears to be lost. However, there is one character by 

 which they may be distinguished : the present species has equal or almost 

 equal ears, and the distal cardinal angle of the posterior ear is nearly a right 

 angle, agreeing with Morton's figure ; the other species, P. scintillatus Conr., 

 has the ears distinctly unequal and the posterior ear obliquely truncated. It 

 is also, in most cases, a little more elongated. 



Pecten (Pseudamusium) scintillatus Conrad. 

 J'fc/i-ii (Etmrneopecteif) sfintilliitits Conrad, Am. Jotirn. Conch., i., p. 140, pi. 10, tij;. 4, 



1865. (Young shell.) 



( 'aiiifitoiicctt's scintilltilits Conr., S. I. Chcrkl. Eoc. Kos. , p. 23, 1.S66. 

 L'aiii/itoiii-i/^s ( /iii/Kinu-nsis Conr., op. cit., p. 23, 1866 (name only). 





