219 



suo 



56. Mytilus edulis, var. latissimus. 



M. e. t. curta, triangulari, latissima. 



Long. M, lat. -77, alt. -5. 



Hab. California Superior ; legit T. Nuttall : sp. unic. in Mus. 



Among the specimens of this species brought by Mr. Nuttall, some 

 appeared exactly likę the normai European type ; oue presented the 

 --well-knownthmstnpedvariety; and that above indicated presents 

 the extreme broad stunted form occasionally seen in this countrv 

 Ali the specimens present the subepidermal apical denticles noticed 

 by Middendorff as (i. e. in form and number) characteristic of the 

 species. 



57. Mytilus Californianus, Conr. Journ. p. 242. pi. 18. f. 15. 

 Godd* Ja^"*^ Barbara, Monterey, San Diego, in rupibus. Mus. 



58. Mytilus bifurcatus, Conr, Journ. p. 241. pi. 18. f. 14. 

 Hab. 1 California. Mus. Gould, Jay. 



This shell is stated by Conrad to inhabit the "Sandwich Islands 

 lUuau, &c.), attached to rocks bare at low water ; " but his authority 

 when unconfirmed by the notes or remembrance of Mr. Nuttall is 

 not binding, as one shell which he assigns to the Sandwich Islands 

 he calls Penia Caiyornica (p. 245). It occurs among Dr. Gould's 

 Mexican War Shells mth the unsatisfactory reference "Californian 

 coast, somevvhere." 



59. ISOGNOMON COSTELLATA, CoUT. 



Perna costellata, Conr. Journ. p. 246. 



Hab. Sta. Barbara, sub saxis. Mus. jay, Nuttall, 

 ^7n habitats of Conrad's Pernce are not satisfactorily ascertained. 

 Ut P.incisam. Nuttall (whose specimen has 6, not 5 teeth) con- 

 firms Conrad s locahty, viz. Sandwich Islands. Of the shell called 

 P. Laliformca, Mr. Nuttall has no specimen, but beHeves Conrad is 

 right lu statmg that it " inhabits with the preceding," i. e. in the 

 Sandwich Islands. The third species, described above, is also assigned 

 by Conrad to the Sandwich Islands, but Mr. Nuttall, who retains 

 his specimen, distinctly refers it to the above locality. 



~~i, ^^^- PfCTEN LATiAURATus, Cour. Joum. p. 238. pi. 18 f 9- 

 Rve. Conch. Ic. pi. 1. sp. 5 ; •Sow. Thes. Conch. vol. i. p. 57. * ' 



Hab. S&n Diego et Sta. Barbara; sub effluxum maris. Mus 

 iNutt., Lum. 



60 5. Pecten MoNOTiMERis, Conr. Journ. p. 238. pi. 18. f. 10. 



Hab. Una cum prsecedente. Mus. Jay. 



Mr. Nuttall considers that this shell is probably a variety of P 

 /atiaiirafus. The young are occasionally found attached to Fuci bv 

 a slenuer byssus. •' 



