﻿358 ANODONTA 



cies in the strong- folds of tlic dorsal slope and the fairly well 

 developed pseudocardinals. I am informed by Mr. Walker 

 that the locality given in the original description was erroneous. 

 The one now stated is correct. 



HOMOGEN^. 



Male and female shells alike, oval to elongate ; beak sculp- 

 ture generally coarse ; embryos filling the entire outer gills in 

 the form of thick, smooth pads ; the ovisacs not separated by 

 sulci. 



Genus AXOUOXTA Lamarck, 1799. 



Mya Li^i<A%\Js, part, Syst. Xat., 1758, p. 1158. 



Limncca Poli Test. Utriusque Sic, 1, 1791, p. 31 ; ii, 1795, P- 



253- 

 Anodonta Lamarck, Prodrome Class, C'oq., 1799, p. 87. — 



Ortmann, Ann. Car. Mus., VIII, 1912, p. 286. 

 Anodon Oki;n, Lehrb. Nat. Zool., 1, 1815, p. 238. 

 Anodontcs CuviiiR, Regne, An., II, 1817, p. 472. 

 Pseiidanodonta Bour'^uignat, Bull. Soc. Sci. Bordeau.x, 1876, 



p. 99. 

 Ptcranodon FjschivR, ALan. Conch., 1887, p. 1005. 



Shell elliptical, iniiated, often slightly winged posteriorly ; 

 beak sculpture consisting of rather numerous more or less 

 parallel ridges,, usually somewhat doubly looped and becoming 

 slightly nodulous on the loops ; surface generally smooth, shin- 

 ing; hinge edentulous, reduced to a mere line, regularly 

 curved ; muscle scars rather faint ; nacre dull. 



Animal with the marsupium occupying the whole outer gills, 

 when filled forming a smooth, very thick, liver-colored pad; 

 gills free from the abdominal sac from one-half to their entire 

 length ; palpi generally large : branchial opening papillose ; anal 

 opening without papillae, though sometimes very slightly cren- 

 iilate; superanal opening generally small, widely se])arated 

 from the anal 



Type, Mytilns cy^nciis TJnnreus. 



The genus Anodonta as here restricted consists of Xaiades 

 with gencralh thin, edentulous shells having a straight or 



