593 REPORT 18G3. 



age. The typos of these species in the Smithsonian Museum a A A r a* too -rn- 

 perfect to determine specifically with any confidence ; and by no means ii* 

 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 witli 



brown. [=O. conchavhila, Cpr.] Another species, elongated, 

 solid, allied to Virginica [var. ruf aides]. San Diego. 



2. Pecten monotimeris, Conr. San Diego. 



3. Pecten ventrtcosus, Sloy.,+tumidus, Sby. [Dead valves, of tha 



form <equisulcatus.~] San Diego. 



4. Mytilm ?edulis \_ = M. trossttlus, Gld., antea]. San Francisco. 



5. Modiola capax, Conr. San Diego. 



0. Venus Nuttattii, Conr. [= V. succincta, Val.] San Pedro. 



7. Venus Jluctifraga, Sby. San Diego. 



8. Tapes grata, Say,= T. discors, Sby., il =straminea, Conr."* San 



Pedro. 



XL 10,20. 9. 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 Saxidomus aratu^ 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, Slake. 

 10. Cyclas, sp. ind. Colorado Desert. 



XT 21,22. 11. Cardium o-uentatum, Gld., n.s. Prel. Rep. 1855. [P. Z. S. 1850, 

 p. 201, = C. substriatum, Conr.] San Diego. [San Pedro, 

 Blake, in text.] 



12. Lucina orbella, Gld. [ = Mysia (Sphcerella) tumida," Conr.] S&E 



Pedro. 



13. Lucina Nuttallii, Conr. San Pedro. 



14. Metodesma ?mbrutincta, Sby.f San Pedro. 



15. Tellina vtcifia, C. B. Ad. [Dead specimens of = Heterodonax 



(" PsammoUa" var.) Pacifica, Com 1 .] San Diego. 



16. Tilliita sccta, Conr. San Pedro. 



17. S )h(enia \_Cry 'ntomyal Calif 'ornica, Conr. San Diego. 



18. Petricola carditwdes, C<mr.\ = cylindracea, Desh. Monterey; San 



Pedro. 



19. Sokaafim Calif ornicnsis, Conr. San Diego. 



20. Gnathodon Lecontii, Conr.,= G. trigonum, Petit. Colorado Desert. 



\_Lecontei is probably the large Texan species : trigonu8*etntM/ 

 dicus is a very distinct shell from Mazatlan.] 



* Neither Dr. Gould, nor Conrad himself, in his later geological writings, appears to 

 liave called to mind the true T. staminea, to which the Smithsonian shells belong. It is 

 the northern representative of T. grata, but quite distinct : v. synonymy under Venu* 

 Petitii riffida, pars. 



f No " Mesodesma " was found among the shells returned to the Smithsonian Institu- 

 tion, nor has any been heard-ot from the coast. Dr. Gould's shell may have been Semele 

 i>a!ckra, which was in the collection. 



78 



