472 



SUPPLEMENT. 



Glaucomya, p. 30?. See An. Nat. Hist. 1855, p. 23. 



Sowerhya, p. 308. (Syn. Isodonta, Buv, p. 314). The cavity described 

 as a " cartilage -pit " receives a tooth of the opposite valve. 

 TelUnidcB, p. 311. Psammobia. 



Fig. 270. Psammobia pallida, Desh. Eed Sea. Left valve, part of the mantle, and 

 retractor of the siphons removed. Siphons much contracted ; a,a, adductors ; 

 p,p, pedal muscles. 



SolenidtB, Glycimeris, p. 320. An. Nat. Hist. 1855, p. 99. 



Fig. 271. Glycimerin siliqua,G'aeran. Newfoundland. 



a, o, adductor muscle; p, pedal muscle; s, siphonal muscle ; /, foot ; <, labial 



tentacles ; g, gills, much contracted and crumpled. 



RiBEiRiA (pholadiformis) Sharpe, 1853. Ged. Joum. Shell gaping at 

 both ends; sub-ovate, rounded in front, elongated and rather attenuated 

 behind ; punctate-striate ; casts of interior with a large umbonal impression 

 (caused by a cartilage-plate, as in Lyonsia?) and a notch in front of it. 

 Fossil.. L. Silurian, Portugal. {Anatinidcn, p. 320.) 



/ScaWea, Ryckholt, 1856. Garb. Tournay. Shell like ^o?/wo»fi?za (p. 323,) 

 with a single cardinal tooth in each valve. 



