592 REPORT—18638. 
age. The types of these species in the Smithsonian Museum appear too im- 
perfect to determine specifically with any confidence ; and by no means in a 
suitable condition to allow of important conclusions being drawn from them. 
98. The third article in the Appendix to the same volume of Reports 
contains a “Catalogue of the Recent Shells, with Descriptions of the New 
Species,” by Dr. A. A. Gould. The specimens were (apparently) in the hands 
of Dr. Gould for examination when he prepared the MS. for the first Report; 
and some of them were included in the “ Mexican War Collections,” B. A. 
Report, pp. 227, 228. “The freshwater shells were collected in the Colorado 
desert and other localities ; the land and marine shells between San Francisco 
and San Diego.” The following is the list of species as determined by Dr. 
Gould, pp. 330-336. The specimens belong to the Smithsonian Institution, 
where a large portion of them were fortunately discovered and verified. 
They were collected by W. P. Blake, Esq., and Dr. T. H. Webb. 
Plate. Fig. No. 
1. Ostrea, sp.ind. Parasitic on twigs; thin, radiately lineated with 
brown. [= 0. conchaphila, Cpyr.] Another species, elongated, 
solid, allied to Virginica [ var. rufoides}. San Diego. 
. Pecten monotimeris, Cour. San Diego. 
. Pecten ventricosus, Sby.,~tumidus, Sby. [Dead valves, of the 
form @quisulcatus.| San Diego. 
4, Mytilus Pedulis [= M. tro:sulus, Gld., antea]. San Francisco. 
5. Modiola capax, Conr. San Diego. 
6. Venus Nuttallii, Conr. [= V. succincta, Val.] San Pedro. 
7. Venus fluctifraga, Sby. San Diego. 
8 
9 
co bo 
9% San 
. Tapes grata, Say,=T. discors, Sby., “=straminea, Conr. 
Pedro. 
. Tapes gracilis, Gld.,n.s. Prel. Rep. 1855. [Quite distinct from 
every other Tapes known from the coast. It is supposed by 
Dr. Cooper to be the young of Saridomus aratus, which in 
shape and pattern exactly accord with the figure and diagnosis. 
But the “ Tapes” is figured without sculpture. The shell was 
not found at the Smiths. Inst.] San Pedro, Blake. 
10. Cyclas, sp. ind. Colorado Desert. 
XI. 21,22. 11. Cardium cruentatum, Gld.,n.s. Prel. Rep. 1855. [P. Z. S. 1856, 
p- 201,=C. substriatum, Conr.] San Diego. [San Pedro, 
Blake, in text. ] 
12. aa orbella, Gld. [ =“ Mysia (Spherelia) tumida,” Conr.| San 
edro. 
13. Lucina Nuttallii, Cony. San Pedro. 
14, Mesodesma ?rubrotincta, Sby.t San Pedro. 
15. Tellina vicina, C.B. Ad. [Dead specimens of = Heterodonax 
(“ Psammobia,” var.) Pacifica, Conr.] San Diego. 
16. Tellina secta, Cony. San Pedro. 
17. Sphenia [ Cryptomya] Californica, Conr. San Diego. 
18. Petricola carditoides, Conr.,= cylindracea, Desh. onterey ; San 
Pedro. 
19. Solecurtus Californiensis, Cony. San Diego. 
20. Gnathodon Lecontit, Conr.,= G. trigonum, Petit. Colorado Desert. 
[ Lecontei is probably the a Texan species: trigonus=men- 
dicus is a very distinct shell from Mazatlan. ] r 
XI. 19,20. 
* Neither Dr. Gould, nor Conrad himself, in his later geological writings, appears to 
have called to mind the true 7. staminea, to which the Smithsonian shells belong. It is 
the northern representative of 7. grata, but quite distinct: v. synonymy under Venus 
Petitii=rigida, pars. 
t+ No “ Mesodesma” was found among the shells returned to the Smithsonian Institu- 
tion, nor has any been heard-of from the coast. Dr.Gould’s shell may have been Semele 
pulchra, which was in the collection. 
