TRANSACTIONS OF WAGNER 



572 



TERTIARY FAUNA OF FLORIDA 



of. If, on the principle of '' once a synonyme always a synonyme," we reject 

 Pectunculus Lamarck, on the ground that the name had already been used for 

 another group by Da Costa in binomial form, we could then retain Lamarck's 

 Nitcula at the cost of adopting Glycymeris for the group usually called Pec- 

 tunculus, which is probably the least inconvenient arrangement of the two. 



According to Herrmannsen Glycymeris was used by Belon, or Belloni, in 

 a quasigeneric sense two hundred years before its use by Klein ; so, even if we 

 resort to non-binomial authors, the latter's name would have no standing. 

 This is probably the reason why Da Costa, who was a man of erudition not 

 prejudiced against the non-binomial writers, adopted the name in its original 

 sense. 



I have already pointed out that the name Nucnlana of Link is merely a 

 modification, on the score of taste, of Nuatla Lamarck. Link was enumerat- 

 ing the Rostock collection, and since it happened that they had only one 

 species, N. rostrata (since separated as Leda by Schumacher), to represent the 

 genus, it follows the modified name ; but there is nothing in this fact nor in 

 the diagnosis of Link to intimate that he intended to subdivide the original 

 Nucula. Link altered many names in this fashion, of which Achathun, for 

 Achatina Lam. ; Anatium, for Anatlfera Lam. ; Cassidca, for Cassis Brug. ; 

 Cerium, for Cerion Bolt. ; Harpalis, for Harpa Lam. ; Limaria, for Lima Lam. ; 

 Nassaria, for Nassa Lam. ; Pectinium, for Pecten Mull. ; P/ciirotoim; for Plenro- 

 toma Lam. ; Tridaclme, for Tridacna Lam. ; Unioniim, for Unto Retz., etc., are 

 examples. For this reason I can only regard Nucnlana as an absolute and 

 exact synonyme of Nucnla Lamarck. 



Subgenus ACILA H. and A. Adams. 



The divaricately sculptured Nuculas in this group, in the recent state, are 

 Pacific in their distribution ; one species, N. divaricata Hinds, extending from 

 Korea (as N. mirabilis Ads. and Rve.) to the China Seas (N. insignis Gould) and 

 probably to the Bay of Bengal (N. Fitltoni Smith), reaches a length of thirty 

 millimetres; another, distinguished by smaller size, more ^vate "form, and a 

 fine, regular, concentric over obsolete divaricate sculpture, is only known from 

 Northern Japan (N. japonica Ball) ; another still (N. divaricata Val., + cas- 

 trensis Hinds, + Lyalli Bd.) extends from the Aleutian Islands to California. 

 In time the group recedes to the Cretaceous, with a much wider geographical 

 range; two species are known from the Greensand of Europe, one (N. Ermaui 

 Girard) from the Upper Cretaceous of Alaska at Atka Island, another from the 



