ON MOLLUSCA OF THE WEST COAST OF NORTH AMERICA. 507 



work had been carelessly printed.) It contains the following species, tho 

 1 )calities quoted in the text from other sources being here omitted : 



oGU. Murex foliatus, Gmel., = 7J/. monodon, Esch. (Cerostoma). San Diego, ? fossil, 



Cassidy. 



9J Murex festivus, Hds. Dead. San Diego, Cassidy. 

 Triton Oregonensis, Redfield (non Jay/ nee Say) =71 cancellation, Midd., 



Rve., non Lam. Straits of De Fuca, Suckley, Gibbs, J. G. Cooper. 



370. Clirysodomus antiquus, var. Behringiana, Midd., one specimen. Straits of Do 



Fuca, Suckley. [Comp. Chr. tabulatusJ] 



f) Chrysodomus Middendorffi-i, Coop., n. s.,= Tritonium decemcostatum, Midd. 

 One specimen on the shore of Whidby's Island. Straits of De Fuca, J. G. 

 Cooper. [ = JBuc. liratum, Mart. This being a remarkable instance of a 

 "representative species," it requires to be minutely criticized. Judge 

 Cooper compared his specimen with 130 eastern shells*, and noted the differ- 

 ences with great fulness and accuracy. A series of Middendorff's Pacific 

 shells having been brought to England by Mr. Damon, and sold at high 

 prices, I made a searching comparison of one of them with the eastern 

 specimens furnished me by Judge Cooper and other most trusty naturalists. 

 According to the diagnosis of Middendoiffii, it should be referred to C. de- 

 cemcostatus, Say, and not to the De Fuca species, as it agrees in all respects 

 with the eastern peculiarities quoted, except that the riblets near the canal 

 are rather more numerous and denned. As it might be suspected that 

 Mr. Damon's shells were mixed, I have made a similar comparison with a 

 shell from the N. W. coast, sent to the Smiths. Inst, by Mr. Pease, and with 

 the same result. On examining the specimens in the Cumingian Collection, 

 in company with A. Adams, Esq., we were both convinced that the eastern 

 and western forms could not be separated. In the similar shells collected 

 by Mr. Adams in the Japan seas there are remarkable variations in the de- 

 tails of sculpture.] 



371. CJirysodomm Sitchensis, Midd. ^incisus, Gld., = cftrs, Rve.]. Str. De Fuca, 



Suckley, Gibbs. 



Nassa mendica, Gld. Puget Sound, Suckley. 



Nassa Gibbsii, Coop., n. s. "Resembles N. trivittata more than N. mendica." 

 Port Townsend, Puget Sound. [In a large series, neither Dr. Stimpson nor 

 I were able to separate Cis species from N. mendica. Similar variations 

 are common in British Nassce. Picked individuals from the Neeah Bay- 

 series would probably be named triwttata, if mixed with eastern shells.] 



Purpura lactuca, Esch. , + M. fevqugineus, Esch., = P. septentrionalis, Rve. Puget 

 Sound, Suckley, Gibbs; Shoalwater Bay, Str. de Fuca, J. G. Cooper. 

 "Abounds on rocks and oyster-beds in Shoalwater Bay, the form and 

 amount of rugosity depending on station. The oyster-eaters are smooth 

 even when young." J. G. C. 



G72. Purpura ostrina, Gld., = P. Freycinetii, Midd., non Desh. +P. decemcostata 

 [Coop., non] Midd. Rocks above low- water mark ; from mouth of Hood's 

 Canal to Str. Fuca ; Puget Sound, common, J. G. Cooper. 



Purpyra lapittus [Coop., non] Linn. [=P. saxicola, Val.] Str. De Fuca, 

 Puget Sound, J. G. Cooper. "Found with P. ostrma, and equally common." 

 [Some varieties run into the New England form of P. lapilhis, sufficiently 

 nearly to justify the identification ; but the bulk of the specimens are easily 

 distinguished by the excavated columella, They pass by insensible grada- 

 tions to P. ostrina, Gld., which is a rare and extreme variety. Many of the 

 shells called P. Freycinetii by Midd. are certainly referable to this species. 

 Some forms pass towards the true P. Freycinetii, Desh., while others are 

 equally close to the very different P. emaryinata, Desh.] 



Purpura emarcfinata, Des'h., = P. Conradi, Nutt. MS. "Upper California," 

 Trask -, San Diego, Trotcbridae. [This appears to be exclusively a southern 

 form = saxicola, var.] 



Monoceros engonatum, Conr., = Jf. unicarinatum, Sby. San Pedro, Dr. Tra*k 

 873. Monoceros hipilloicles, Conr.,=J/.^wcfrtfwH ; Gray. San Pedro, Dr. Tra*k. 



83 



