1856.] 



285 



Formations iu 



ascending opder. 



12 3 4 5 





 (( 

 c( 



ft 

 u 

 u 

 u 



(( 



(( 

 <( 



Gen. NUCULA 



N. saBNA3UTA, Hall & Meek, Mem. Ac. Arts & Sci. Bost., v. 5,N. Ser. p. 384 

 N. vENTRicosA, Hall & Meek, " " " " 385 



N. sciTOLA, Meek & Hayden, Proceed. Acad. Nat. Sci. Phila., vol. 8, p. 84 

 N. EvANSi, Meek & Hayden, " 



N. EQUiLATERALis, Meek & Hayden, 



N. SUBPLANA, Meek & Hayden, " " 85 



N. CANCELLATA, Meek & Hayden, 

 N. PLANOMARGiNATA, Meek & Haydcn, 

 N. 0B30LETASTSIATA, (accompanying paper) 



Gen. PECTUNCULUS 

 P. SiouxENSis, Hall &Meek, Memoirs Am. Ac. Art. & Sci. v. 5, N. S. p. 384 



Gen. SIMOPSIS. 



L. PARVULA 



Phciunculina parvula, Meek & Hayden, Proc. Ac. Nat. Sc. Phila., v. 8, p. 85 



Gen. CUCULL^A 

 C. Nebrascensis, Owen, Kept. Iowa, Wis, and Min. tab. vii. fig. 1 and la 

 G. coRDATA, Meek & Hayden, Proc. Acad. Nat. Sc. Phila., vol. 8, p. 86 

 0. Shumardi, Meek & Hayden, " " " " 

 C. ExiGUA, Meek & Hayden, (see accompanying paper) 



Gen. MYTELUS. 



M. ATTENUATua, Meek & Hayden, Proc. Acad. Nat. Sc. Phila., vol. 8, p. 86 

 M. Galpinianus, Evans & Shumard, " " " vol. Y, p. 164 



M. suBARcuATus, Meek & Hayden, (see accompanying paper). 



Gen. AVICULA. 

 A. TRIANGULARIS, Evans & Shumard, Proc. Ac. N. Sc. Phila,, v. 7, p. 163 

 A. LiNGUiFORMis, Evans & Shumard, " " " " 



Avicula, undt. Owen's Report, Iowa, Wis. and Min. tab. vii. fig. 10 



A. Haydeni, Hall & Meek, Mem. Acad. Arts & Sci. Bost., v. 5, N. Ser. p. 382 



Gen. GERVILIA. 

 G. SUBTORTUOSA, Meek & Hayden, (see accompanying paper) 



Gen. INOCERAMUS. 



1. problematious, Schlotheim, sp. 1820. Petrf. p. 312 



/. myteloides, Mantell, Geol. Suss, p, 215, pi. 28, fig. 2. 



IK?) I. Barabini, Morton, Synopsis Org. Remains, page 62 , 



1. Sagensis, Owen, Report Iowa, Wisn, and Min, tab. vii. fig. 3 



I. NEBRASCENSis,*Owen, " " " tab, viii. fig. 1 



I. suBL^vus, Hall & Meek, Mem, Am, Ac. Art. & Sc. Bost,, v, 5, N. S. p, 386 



I. coNVExus, Hall & Meek, " " ' 



I. TENUiLiNEATUs, Hall & Meek, " " " 387 



I, CoNRADi, Hall & Meek, " < " 



I. PRAGiLis, Hall & Meek, " <' 388 



I. VENTRicostJS, Meek & Hayden, Proc, Ac, Nat, Sc. Phila,, vol, 8, p. 87 



I, PBRTENUis, Meek & Hayden, (accompanying paper) 



I, iNCURVUS, Meek & Hayden, " " 



Gen. PECTEN. 

 P. RiGiDA, Hall k Meek, Mem. Am. Ac. Arts & Sc. Bost., vol.5, N, S, p, 381 

 P. Nebrascensis, Meek & Hayden, Proc. Acad. Nat. Sc. Phila., vol. 8, p. 87 



* Is Prof. Tuomy's /. biformis, Proc. Ac. N. S. Philada., vol. 7, p. 170, identical with this ? 



