72 AMERICAN JOURNAL 



The value of this subdivision is doubtful. 



Subgenus Cranopsis, Dall. Attached ; upper valve with two 

 slender pointed apophyses divaricating from the internal apex of 

 the upper valve. Type Crania Parisiensis, Defrance, Davidson, 

 Mem. Lin. Soc. Norm, x, pi. xiii, f. 23 a, b, 1856. 



Genus Craniseus, Dall. Fixed valve divided by a transverse 

 and a longitudinal median septum into three cells, the posterior 

 of which contains the muscular impressions and the rostrellum. 

 Tyye Crania tripartita, Munster, sp.. Davidson, Mem. Lin. Soc. 

 Normandie, 1. c. fig. 21, 1856. 



This is a very strongly marked section, and it seems extraoiv 

 dinary that it should have been allowed to remian with the typi- 

 cal Cranice so long. The septa are not identical with the rostrel- 

 lum. 



Spondylobolus, McCoy (misprinted, on pp. 100, 151, 163, 164, 

 165, as Spondylobus), appears, as stated by McCoy, to be more 

 nearly related to the Lingulido? than to the Craniidce. 



Pholidops, Hall, appears congeneric with Pseudocrania, but, 

 as it is chiefly known from casts, may be established by future 

 researches as distinct. 



Genus CRANIA, Retzius. 



Crania, Retz., Schrift. Berliner, Ges. Naturf. Freunde, Bd. ii, 

 p. 72, 1781. 



= Cranicella, Raf., 1815, 4" Orbicula, Cuvier, 1798, + Orbicula 

 (pars), Lamarck, 1799, -f- Discina sp. Turton, 1822, -f- 

 Anomia sp. Lin., 1760, -f- Patella sp. Muller, 1776, + 

 Siphonaria sp. Quenstedt, 1852 ! -j- Criopus, Gray, 

 1821. 

 The full synonymy of this unfortunate group will be found in 



the report alluded to, with an exhaustive discussion of the 



nomenclature of the type and some other species. 



Type Crania craniolaris, Lin. sp. 



= Anomia craniolaris, Lin., S. N. xii, i, pt. ii, p. 1150, No. 



216, 1767. 

 = Crania brattensburgensis, Retz. (pars), 1. c. p. 73, 1781. 

 = Crania nummulus, Lam., An. s. Vert. Ed. i, vi, p. 238, No. 



2, 1819. 

 = Crania personata (part), Lam., 1. c. p. 238, 1819. 

 = Ostracites numismalis, Beuth., Jul. et Mont. subt. p. 130, t. 



7, No. 46, 1116, fide Bronn. Ind. Pal. 



A fossil species from Sweden, confounded with the recent 

 species by Retzius, Gmelin, Dillwyn, Chemnitz and Lamarck. 



