IIG lAI.IKOUSIA A<;AnEMY OK SCIENCES. 



37. Lima (Mantellum) dehiscens Ctniriiil. 



Lima dehiscnis Con, ]wn. I'hil. Aciul. Sci., Vol. VII, 1S37, |>. 247, I'l. XIX, dv;. 7. Cooper, 7tli 



Ann. Ri'pt. Cat. St. Min., iSsS, p. 245. Dai.i., 'I'lans. Waynir Inst. Sci., Vol. Ill, r.iit 4, 



iSy8, p. 769. 

 Lima on<rii/<i/is {nut o( An. & Rve.) of Cari-f.ntkr, Riit. Assn. Rept., 1863, p. 645. Kf.ep, West 



Coast Shells, p. 16.S, fiii. 142, 1S92. Williamson, Pioc. U. S. Nat. Mus., Vol. XV, 



1S92. p. 193. 



Shell equivalve, compressed, obliquely oval, thin, white; anteiif)!' side straijjht ; posterior 

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

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

 crentilated. 



Dimensions. — Long, i •., mm.; alt. 18.5 mm. ; diam. 8 mm. 



Looks like ail ol)li(jiK'Iy (lol'onncd Pcclen. Speciiuoii ideiilificfl l)_v Dr. Dall. 

 Uaro in lower San Pedro .serie-s of Deadman Island; one specimen collected 

 l.y Mis. Oldroyd. 



Liring. — Montefcy to San Diego (Cooper): Santa Catalina Island (Arnold). 

 Pleistocene. — San Pedro (Mrs. Oldroyd). 

 Pliocene. — Santa Barbara (Cooper). 



Superfamily ANOMIACEA. 



Family XI. ANOMIID/E. 



GeiuLs Pododesmus 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 rudis Brod. is a characteristic species. 



Section Monin Gray. 

 Adult hole or foramen large. 



Pododesmus machroscliisma Do.sliayes is a characteristic species. 



38. Pododesmus (Monia) macroschisma Dcshayex. 



Anomia 7nacroscltisma Desh., Reeve, ZooI. Soc. Ciivierienne, 1839, p. 359. Mag. Zool., 1841, PI. 



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



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

 Placwianoniia macroschisma Desh., Gray, Proc. Zool. Soc, 1849, 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, 7tli Ann. Re])!. Cal. St. Min., 



188S, p. 260. Keep, West Coast Shells, 1892, p. 163, fig. 137. 

 Placunaiiomia {Monia) macroschisma Desh., Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892, 



p. 194. 

 Pododesmus (Monia') macroschisma Desh. ^= Placunanomia ccpio Gray = Plactinanomia a/ope 



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



