174 PROCEEDINGS OF THE CALIFORNIA 



20Ancylas patelloides Lea. The locality in the Geog. Cat_ 

 is wrong, it being the upper Sacramento Kiver, Dr. Trask. Specimens 

 from near Spokan River, Washington Territory, Hemphill, are so small 

 and fragile, that I refer them with doubt to this species, their outline agreeing 

 best with it, though approaching that of A. Kootaniensis Bd., which 

 I call a variety of it in my synopsis, on p. 101. 



21 Acroloxus Nuttallii Hald. (Binn.) This interesting species was 

 found common in the lower part of Snake River, Washington Territory, by Mr. 

 Hemphill, and shows the peculiar sinistral apex very plainly, many of the speci- 

 mens being half an inch long. One very small specimen, found by Mr. Yates, 



n Alameda County, seems the same, agreeing in dark reddish color, thickness, 

 outline, sinistral apex, etc. 



22 AssimineaCalifornica, Tryon {Cp.) " H y d r o b i a " Tryon. 

 Although belonging 'to the marine family Littoritnda, this little shell has habits 

 similar to those of the Alexia, being found with it along Mission Creek in im- 

 mense numbers. It also inhabits Islais and Oakland Creeks. I find the ani- 

 mals of all these localities alike, and agreeing with the generic characters as given 

 l)y authors. It is the first of the genus yet determined to exist in the United 

 States, though some eastern " Hydrobias," etc., have been suspected to belong 

 10 it. The animal lives a week or more in a bottle dampened with salt water, 

 while the Pomatiopsts, though similar enough in shell to have been confounded 

 Nvith this, will die quickly in salt water. The eyes are near the end of erect 

 tentacles. 



23 Yalvata sincera Say. Specimens from near Salt Lake {Hemphill), 

 » eem to be this Mississippi Valley species, not before reported from west of the 

 ^locky Mountains. 



Besides the above, Mr. Hemphill brought from the San Diego mines and sur- 

 . ounding mountains, none of which rise over 7,000 feet above the sea, 

 i!ie following, showing that the species found there are, in a great degree, 

 i.istinct from those of the neighborhood of the Bay, only about thirty-five miles 

 1) the south-west. 



24Lysinoe Traskii A'cmc. The typical, thin flattened form. 



25 Hyalina arborea Say. 



26 Conuius chersina Say. 



27 Pseudohyalina Mazatlanica Pf. 



28. Yallonia minuta Say. Nos. 25 and 26 were found by Mr. Voy, 

 '() miles north of these mines, with "Ps. minuscula Lea," teste New- 

 I- )mb. Were the last not young of No. 27 ? 



29Limnophysa humilis Say. 



30 Physadiaphana Tryon. 



The only fresh water shells brought from near the Bay were : 



31. Liranophysa bulimoides Lea. Rare. 



32 PhysaGabbii Tryon, vars. "Traskii" Lea, and D ' r b i g n y - 

 ii n a Lett- 



