684 REPORT 18G3. 



before considered as essentially tropical. Along with- these are not only some 

 species of types hitherto regarded as almost exclusively Asiatic, as Verticordia, 

 Solariella, and Fulvia modesta, but also some which belong to the sub-boreal 

 district, as Lucina borealis, Venericardia borealis, and Crenella decussata. The 

 latter belongs to the British, and not to the N. England form. 



129. Of the bleudingof the temperate and tropical faunas on the peninsula of 

 L. California we are still in ignorance. All we know is, that at Margarita Bay 

 the shells are still tropical, and that at Cerros Island they are strangely inter- 

 mixed. There is peculiar evidence of connexion between the faunas of the penin- 

 sula and of S. America, not only in the land-shells (v. anted, p. 630), but in 

 some of the marine forms. Beside identical species with wide range, as many Ca- 

 lyptraeids, the following are coordinate between the North and South Paciiic: 



Upper and Lower California. 

 Netastoma Darwinii. 

 Solecurtus Californianus. 

 Semele rupium. 

 Callista var. puella. 

 Ohama pellucida. 

 Liocardium substriatum. 

 Axinsea (Barbarensis.) 

 Verticordia novemcostata. 

 Pecten aequisulcatus. 

 Siphonaria thersites. 

 Tonicia lineata. 

 Acmaea patina. 

 Acnuea persona. 

 Scurria mitra. 

 Chlorostoma funebrale. 

 Mitra maura. 

 Eanella Californica. 

 Priene Oregonensis. 

 Trophon multicostatus. 



South America. 



N. Darwinii. 



S. Dombeyi. 



(Ditto, Galapagos.) 



C. pannosa. 



C. pellucida. 



L. Elenense. 



A. intermedia. 



V. ornata. 



P. ventricosus. 



S. lateralis, &c. 



T. lineolata. 



A. scutum, D'Orb. 



A. " Oregona," H. C. 



S. scurra. 



C. nice stum. 



M. maura. 



R. ventricosa. 



P. cancellata. 



T. Magellanicus. 



Time and space do not avail for pointing out further relations with exotic 

 faunas ; which indeed will be performed with greater correctness after Dr. 

 Cooper shall have published his complete lists. 



130. Eor the sake of avoiding the inconvenience of trinomial nomenclature, 

 the subgeneric and varietal names have often been cited in this Eeport instead 

 of the generic and specific, in order that the exact form of the shell quoted 

 might be more quickly determined. The diagnoses of all the new species 

 here tabulated are written for the press, and will shortly appear in the dif- 

 ferent scientific journals. Additional specimens will probably prove several 

 forms to be conspecific which are here treated as distinct. In the present 

 state of the science, absolute certainty is not to be attained. The object of 

 the writer* has been principally to bring together the works of his prede- 

 cessors, and so to arrange and describe the new materials that those who 

 continue his labours may be able to draw their own conclusions from existing 

 data. In order to facilitate reference, a brief index is here given of the 

 subject-matter of the former and of the present Reports. 



* The best thanks of the writer are due to Hugh Cuming, Esq., for the free use of his 

 collection ; to Messrs. H. & A. Adams, Hanley, Beeve, and Sowerby, for aid in identifying 

 specimens ; to the officers and naturalists connected with the Smithsonian Institution ; 

 to Dr. A. A. Gould, for very valuable corrections ; and generally to authors and friends, 

 who have kindly rendered him all the assistance in their power. He earnestly invites 

 criticisms on the subject-matter of the two Reports ; in order that they may be embodied, 

 and errors corrected, in the Manuals of the West-Coast Mollusca which he has undertaken 

 to prepare for the Smithsonian Institution. 



Warrington, Aug. 22nd t 1864. ^ ,_~ 



