Dall.] 



252 



[March 16, 



mesodesmid;e Desk. 



Ceronia Gray. 



C. arctata, p. 80. C. deaurata, 

 p. 81. 



amphidesmi»;e Desh. 



Cummgia Br. & Sby. 

 C. tellinoides, p. 79. 



TELLINID^E Desh. 



Macoma Leach. 



M. fusca, p. 93. M. proxima, 

 p. 95. 

 Angulus Men. 



A. tenera, p. 97. 

 Peronsea Poli. 



P. tenta, p. 96. 



PETRICOLID.E. 



Petrieola Lam. 



P. pholadiformis, p. 90. P. 

 dactylus, p. 92. 



VENERID.E Desh. 



Callista Poli. 



C. convexa, p. 131. 

 Mercenaria Schum. 



M. mercenaria, p. 133. M. 

 notata, p. 135. 

 Liocyma Dall. n. g. 



L. fluctuosa Gld.,p. 136 (v. d.). 

 Gemma Desh. 



G. gemma, p. 137. G. man- 

 hattensis, p. 138. 



Group Corbiculacea. 



CORBICULID.E. 



Sphoerium Scop. 



S. similis, p. 101. S. partu- 

 meium, p. 103. S. rhomboi- 

 deum, p. 104. S. Vermon- 

 tanum, p. 105. S. trunca- 

 tum, p. 106. S. tenue, p. 

 107. S. securis, p. 107. S. 

 occidentale, p. 108. 



pisiDiiDiE Gray. 



Pisidium Pfr. 



P. dubium, p. 109. P. Adamsi, 

 p. 110. P. compressum, p. 

 110. P. Eequilaterale, p. 



112. P. ferrugineum, p. 



113. P. abditum, p. 113. 

 P. variabile, p. 115. P. ven- 

 tricosum, p. 116. 



CARDIACEA. 



Cyprina Lam. 



C. Islandica, p. 

 Cardium Linn. 



129. 



Group Cardiacea. 



C. pin- 



gantulum, p. 141 



nulatum, p. 141. 

 Liocardium (Sw.) Moerch. 



L. Mortoni, p. 143. 

 Serripes 1 Beck. 



C. Islandicum, p. 139. C. ele- S. Gronlandicus, p. 144. 



1 Aphrodite is in use for a well known genus of marine worms. The Serripes ? 

 {La Perousii) of the N. W. Coast of America, hardly to be distinguished by the 

 shell from the type of the genus, has a smooth, cylindrical foot, without serrations. 

 This throws some doubt on the value of the genus. 



