372 ZOOLOGY. 



in. I obtained the most perfect adhering to rocks below low water, in a place where they 

 were not likely to be rolled. Those found on oyster-beds are usually smooth, even when quite 

 small. 



"The form, also, seems to vary considerably in different localities; some from Puget Sound 

 being much larger and more elongated, though found also of the usual form near by."— J. G. C. 



PURPURA OSTRINA. 



Purpura ostrina, Gould, Expl. Exped. Shells., p. 244. — Idem Atlas, fig. 310; Carp. Rep. p. 340. 



"Purpura Freyciiutii," Middend.; non Desh. 



Purpura decemecostala, Midd. Beitrage 11, 116; pi. i.x, f. 1,2, 3. 



Hob. — Straits of Fuca ; Puget's Sound ; Dr. Cooper. 

 Quite a different species from P. Freycinetii, of Deshayes, with which it was confounded by 



Middendorff, though he also named and described it as new. Whether his or Dr. Gould's 

 name has the priority I have not the means of deciding. On rocks above low water mark, 

 from the mouth of Hood's Canal to Straits of Fuca; common. 



PURPURA LAPILLUS. 



Purpura lapiUus, Linn, Midd. Gould, Carpenter; op. cit. 



/JaJ.— Sitka Ochotsk ; White sea ; Middendorff. Straits of Juan de Fuca; Puget's Sound ; Dr. Cooper. 

 Equally common with the last species, and found together with it. 



PURPURA EMARGINATA. 



Purpura marginata, Desh. Eev, Zool. 1839.— Magasin de Zool. Moll. pi. 25; 1841.— Reeve, C. I. Pruss. x, p. 46. 



Carp. Rep. p. 340. 

 Purpura Conradi, Nutt. Mbs., Jay's Catal. No. 8972. 



fljft.— Upper California: Dr. Trask. San Diego ; Lieut. Trowbridge. 



This shell is, no doubt, a California species, whence several were sent by Dr. Trask. Mr. 

 Reeve mentions specimens in the British Museum, collected by Mr. Nuttall in that country. 

 There is probably an error in M. Deshayes statement that it inhabits New Zealand. 



MONOCEROS ENGONATUM. 



Pu'pura (Mcmoceros) engonala, Conr. in Journ. Acad. Phila. VII, p. 26 ; pi. 20, p. 17. 

 " Monoceros mgoiutium, Conr." Carp. Report, p. 201. 



" Monoceros unicarinatum, Reeve, C. I. sp. 1 ; new, pi. I, f. 1 ; nee. Bjn. pi.; non Sowb. nee. Desh."— Carp. Eep. 201. 

 " Monoceros umcarinatum, Sown, var." Jav, Cat No. 9067. N. B.— The type is quoted by Dr. Jay as synonymous 

 with Purpura spirata, Blaiuville. 

 Hub.— B&y of San Pedro, Upper California ; Dr. Trask. Santa Barbara ; Nuttall. 



From the above citations, Avhich might be further extended, it will be seen that there is much 

 difference of opinion concerning the synonymy of this species. Our specimens, of which four 

 were sent by Dr. Trask, agree entirely with Mr. Conrad's figure and description. They differ 

 materially from Kiener's figure of Fiirjncra spirata from the Sandwich Islands, and still more 

 from Reeve's figure 2, specimen 1, of his plate I. At the same time they are possibly identical 

 as species. This was first published by Mr Conrad in 1837. 



