178 . Bryant Walker 



Genus ALASMIDONTA Say, 1818. 



Subgenus I'RESSODONTA Simpson, 1900. 



I have recently (162, p. 2) proposed to supercede this name with that 

 of Calceola Sw., 1840, on the ground of priority. Dr. Dall has since called 

 my attention to the fact that Calceola had already been used by Lamarck 

 in 1799 for a coral. Simpson's name will therefore stand. 



Subgenus PROLASMIDONTA Ortmann, 1914. 



Prolasmidonta Ortmann, Naut., XXVIIT, 1914, p. 44. 

 Type: Uiiio hcterodon Lea. 



Subgenus PEGIAS Simpson, 1900. 



According to Ortmami (81, p. 45) this group is a subgenus of .^Uasnil- 

 donta. 



Subgenus RUGIFERA Simpson, 1900. 



AlvASMIDONTA MARGINATA Say. 



Unto calc coins sciotincola De Gregorio, Aloll. di aq. dul. di Amer., 19 14, p. 

 24, pi. IX, fig. 3. 

 Frierson (42, p. 7) has identified Alasmodon scrlptiiin Raf. with this 

 species, but Say's name has priority. 



Alasmidonta raveneuana (Lea). 



Frierson (42, p. 7) has identified Alasniodon atropnrpiircinn Raf. as be- 

 ing this species. If identifiable from the original description, it has priority. 



On the basis of these identifications, he would substitute Dcciirainbis 

 Raf., 1831. for Ritgifcra Simp, as the subgeneric name. 



Genus SIMPSONICONCHA Frierson, 1914. 



Hcniilasfcna Simpson, non Agassiz, Syn., 1900, p. 673; Desc. Cat., iQi.], p. 



323- 



Simpsonaias Frierson, Naut., XXVIII, 19 14, p. 7. (Preoccupied.) 

 Shnpsoniconcha Frierson, Kfaut., XXVIII, 1914, p. 40. 

 Type: Alasiiiodouta ainbigua Say. 



For note on this name, see Walker, 162, p. 4. 



Subfamily LAMPSILIN^ Ortmann, 1912. 



Genus PTYCHOBRANCHUS Simpson. 



Frierson, having identified (42, p. 7) Obliqitaria fasciolaris Raf. with 

 P. phaseolus (ITild.), has designated it as the type of BUipsaria Raf. and 

 gives the latter priority as the generic name. 



