t84 REPORT— 18C3. 



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

 species oftyiH.vs hitherto regarded as almost exclusively Asiatic, as VerliconJia, 

 tSulariella, and Fulvia modesta, but also some whicH belong to the sub-boreal 

 district, us Liuiaa borealis, Venericardia horecdis, and Crtndla decussata. Tho 

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



12'.^. Ot the blendingof the temperateand tropical faunas on the peninsula of 

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

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

 mixed. There is pecrJiarendence of connexion between the faunas of the penin- 

 sula and of S. America, not only in the land-shells (i'. anted, p. ij'60), but in 

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

 lyptrands, the following are coordinate between the North and South PaciHc: — 



Uj>per aiul Lower California. 

 iNetastoma Dai-winii. 

 Solecurtus Calif oruianua. 

 St'mele rupium. 

 Callista v(ii: puella. 

 Chania pellucida. 

 Liocardium substriatum. 

 Axina?a ( Barbarensis.) 

 Verticonlia novemcostata. 

 I'ecten jcqui.siik-atus.* 

 Siphonaiia thersites. 

 Tonicia liueata. 

 Acni;ea patina. 

 Acmie.i persona. 

 Scurria niitra. 

 Chloro.stonia funebrale. 

 Mitia inaura. 

 Raiiella Califomica. 

 Priene Oregonensis. 

 Ti'ophou multicostatus. 



South America, 

 N. Darwinii. 

 S. Dombeyi. 

 (Ditto, Galapagos.) 

 C. pannosa. 

 C. pellucida. 

 L. Elenense. 

 A. intermedia. 

 V. omata. 

 P. ventiicosus. 

 S. lateralis, &c. 

 T. lineolata. 

 A. scutum, D'Orh. 

 A. " Oregona," If. C. 

 S. scurra. 

 C mo?stum. 

 M. niaura. 

 li. 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. For the sake of avoiding the inconvenience of trinomial nomenclature, 

 the subgeneric and vaiietal names have often been cited in this Report 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 tlie 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. II. & A. Adams, Ilanley. Keeve, and ISowerby, for aid in identifying 

 specimens; to tlie ofRoers and naturalists connected with the Smithsonian Institution; 

 to Dr. A. A. Gould, for verj j-a!uable corrections; and generally to autliors and friends, 

 who have kindly rendei d him all the assistince in their power. He earnestly invites 

 criticisms on the subject-matter of the two Re|Wrts ; in order tliar they nuiy be embodied, 

 and errors corrected, in the Manuals of the ^V^^sl-Coast Mollusca which he lias uiidertakea 

 to prepare for the Snnthsonian Institution. 

 Warrington, Auj. 'I'ind, ISGl. ^ __ 



