116 CALIFORNIA ACADEMY OF SCIENCES. 



37. Lima (Mantellum) dehiscens Conrad. 



Lima dehiscens Con., Jour. Phil. Acad. Sci., Vol. VII, 1837, p. 247, PI. XIX, fig. 7. Cooper, 7th 



Ann. Rept. Cal. St. Min., 1S88, p. 245. Dall, Trans. Wagner Inst. Sci., Vol. Ill, Part 4, 



1898, p. 769. 

 Lima orieniah's {not oi At). & RvE.) of Carpenter, Brit. Assn. Rept., 1S63, p. 645. Keep, West 



Coast Shells, p. 168, fig. 142, 1892. Williamson, Proc. U. S. Nat. Mus., Vol. XV, 



1892, p. 193. 



Shell equivalve, compressed, obliquely oval, thin, white; anterior side straight; posterior 

 rounded ; umbones eared, posterior ears acutely pointed ; surface smooth, radiately striate with fine 

 grooves ; hinge-area long, narrow, triangular ; cartilage pit central, prominent ; margin finely 

 crenulated. 



Dimensions. — Long. 13 mm.; alt. 18.5 mm. ; diam. 8 mm. 



Looks like an obliquely defornied Pecten. Specimen identified by Dr. Dall. 

 Rare in lower San Pedro .serie.s of Deadraan Lsland; one specimen collected 

 by Mi's. Oldroyd. 



Living. — Monterey to San Diego (Cooper): Santa Catalina Island (Arnold). 

 Pleistocene. — San Pedro (Mrs. Oldroyd). 

 Pliocene. — Santa Barbara (Cooper). 



Superfamily ANOMIACEA. 



Family XI. ANOMIID^. 



Genus Pododeemus Philippi. 



Shell suborbicular, very variable, translucent and slightly pearly within ; attached by a plug 

 passing through a hole or notch in the right valve ; a single conspicuous byssal scar on the disk ; 

 valves radiately grooved ; hinge unarmed. 



Pododesmus rudin Brod. is a characteristic species. 



Section Monia Gray. 

 Adult hole or foramen large. 



Pododesmus rnachroschisma Deshayes is a characteristic species. 



38. Pododesmus (Monia) macroschisma Deshayes. 



Anomia viacroschisma Desii., Reeve, Zool. Soc. Cuvierienne, 1839, p. 359. Mag. Zool., 1841, PI. 



XXXIV. MiDDENDORF, Beitr. Mai. Ross., Bd. Ill, 1849, p. 6. Philippi, Abbild. 



beschr. Conch., 1850, p. 132, PL I, fig. 4. 

 Placunanomia macroschisma Desh., Gray, Proc. Zool. Soc, 1S49, p. 121. Cat. Anam. Brit. Mus.. 



1850, p. 12. Carpenter, Brit. Assn. Rept., 1863, p. 646. Trvon, Syst. Conch., 



Vol. Ill, p. 294, PI. CXXXI, fig. 76, 1884. Cooper, 7th Ann. Rept. Cal. St. Min., 



1888, p. 260. Keep, West Coast Shells, 1892, p. 163, fig. 137. 

 Placunanomia (Monia) macroschisma Desh., Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892, 



p. 194. 

 Pododesmus {Monia') macroschisma Desh. = Placunanomia ccf>io Gray = Placunanomia alope 



Gray, {fide Dall, Trans. Wagner Inst. Sci., Vol. Ill, Part 4, 1898, p. 780). 



