116 TnE NAUTILUS. 



Length 14.25 ; width 8.00 ; aperture length, 7.00 ; width 4.00 mill, 

 adult. 



Length 10.00; width 5.25; aperture length, 5.00; width 3.00 

 mill. juv. 



Type locality. Hayes Creek, near Ward, Montana, in tlie Bitter 

 Root Mountains, altitude 382'> feet. 



Types in collection of L. E. Daniels. 



Tiiis Lymnaiid belongs to the paluslri's group and is related to 

 Galba valilii ('' Bt^ck " jMollt-r). It differs from that s|)ecies in 

 being niore solid, the periostracum more polished, and the aper- 

 ture rounder. The greatest difference is in the inner lip, wliich 

 is roundly and evenly reflexed over the umbilicus, lacking the 

 twist so noticeable in this group, and resembling in this respect such 

 species as Galba huUmoldes cockerelU and Galba caperata. Half- 

 grown specimens might easily be mistaken for Galba btilimoides, 

 the s[)iral lines and narrow umbilical chink, however, easily separat- 

 ing them. Vahlii has not been found south of the ooth parallel, and 

 there is, therefore, a wide gap in the range of the two species. 



The specimens at hand show some variation, one specimtMi being 

 very obese ; while another, which is believed to be typical, has a 

 rather long, turrtted spire. The young, half-grown specimens are 

 always obese. The specimens were collected by Mr. L. E. Daniels 

 in April l'J12. 



RADIX AURICULAKIA AT CAMBRIDGE, MASSACHUSETTS. 



BY W. K. CLAPP. 



About four years ago, a dam was built across the Charles River 

 at Boston. Above this dam, nearly four miles of the river, which 

 was formerly salt and full of marine life, is now fresh water. In the 

 Nautilus, Vol. 2o, \u 132, Mr. C. W. Johnson writes of a colony 

 of Modiolus dciinssKS v. plicatulus Lam., which until a few years ago, 

 lived about two mih'S above the dam. I collected a very fine set of 

 Paludestrina salsa Pils., and a few Odostomia bisuturalis and trlfda, 

 in l.'^93, nearly three miles above where the dam now stands. But 

 records of the marine molluscan fauna of this part of the river seem 

 to be very scarce. 



