12 Tin: NAITJLUS. 



The specimens were dredged in about 50 fathoms. The um- 

 bones in .1. ivillctli are G.O mm. behind the anterior end of the 

 shell; ill A.' compa'da about 5.5 mm., the result being that the 

 latter has a more triangular outline. The type of A. loilldti is 

 number 216364 of the catalogue of mollusks of the U. S. Na- 

 tional Museum. 



NOTES ON BOREAL LAND AND FRESHWATER SHELLS. 



BY W.M. H. DALL 



The National Museum has received a email lot of fresh-water 

 shells from Dr. T. E. Winecoff, stationed at Fort Yukon, 

 Alaska, nearly on the Arctic circle, which are of more than 

 ordinary interest. They were collected from a small pond near 

 the fort and the large Lymnnca abounded in such numbers as 

 to give a pinkish tint to the water in which they were, accord- 

 ing to the collector. The species are: 



Lymnaea appressa Say, rather small for the species, and of a 

 brownish tint not unlike the usual color of L. pahistris. 



Lymnaea pahistris Miiller. Ordinary type and size. 



Lymnaea emarginata mighekii Binney. Not known so far 

 northwest. 



rianorbis trivolvis Say, medium size, abundant. 



Planorbis crista Linne, one specimen. Nearest known locality 

 is Carberry, Manitoba. 



Fisidium veskulare Sterki, one specimen. 



During a cruise in Bering Sea last summer, Mr. G. Dallas 

 Hanna touched at St. Mathew Island in the northern part of 

 Bering Sea. From small ponds in the island he obtained the 

 following species: 



Aplexa kypnorum Linne. 



Planorbis jmtvus Say. 



Valvata mergcUa Westerlund. 



Pisidium scutellatum? Sterki. 



Succinea chry.sis Westerlund. 



