No. 3. 



REPORT UPON THE LAND SHELLS COLLECTED ON THE SURVEY. 



BY W. G. BINNEY, 



MEMBER OF THE ACADEMY OF NATURAL SCIENCES OF PHILADELPHIA. 



The terrestrial mollusks of the Pacific region of the United States are entirely distinct from 

 those of any portion of the Union east of the Kocky mountains. No species has, as yet, heen 

 detected on both sides of this insurmountable barrier. The types, also, are quite different. 

 Instead of the fragile, horn colored shell of our western States, the shells are large, solid, and 

 endowed with the rich coloring of the tropical species. Our knowledge of them is still very 

 imperfect. Future research will probably bring to light many new species and interesting facts 

 relating to their habits and their geographical distribution. 



The helices of California and Oregon are characterized by a very peculiar indentation and 

 granulation of their surface, and often by the presence of a broad, revolving band on the body 

 whorl. This latter peculiarity exists in one-half of the species hitherto observed. 



None of the shells brought by this expedition are new to science. I have, however, given full 

 descriptions of all, as those that have been published are very brief, and some have not been 

 noticed by American authors. 



The measurements are given in millimetres, the French system being the most convenient 

 and the one generally adopted by European naturalists. 



No. 1. HELIX FIDELIS, Gray. 



Testa subconica, solida, alba, castanea aut nigra, striata, et lineis volventibus induta ; spira 

 elevata ; anfr. 7 regulariter accrescentes, fascia nigra aut castanea cincti ; sutura impressa ; 

 subtus convexa, laevigata, nigra, profunde umbilicata ; apertura depresso-rotundata, intus 

 fasciata ; columella callo levi induta ; labrum album aut fuscum, ad umbilicum reflexiusculum. 



SYNONYMS AND REFERENCES. 



Hdix fidelis, GRAY, Proc. Zool. Soc. p. 67, anno July, 1834. 

 CHEMNITZ, ed. 2, p. 321, t, LVII, f. 12-13. 

 PFEIFFER, Monog. Hel. Viv. I, p. 338 IB. Ill, p. 229. 

 REEVE, Con. Icon. No. 657. 



Helix nuttalliana, LEA, Am. Phil. Soc. VI, 88 ; pi. xxiii, f. 74, anno December, 1834. 

 BINNEY, Boston Journ. Nat. Hist. Ill, 369 ; pi. xii. 



Terrestrial Mollu&ks, II, 159, III ; pi. xviii. 

 DBKAY, Nat. Hist. New York, p. 46. 



