NATURAL SCIENCES OP PHILADELPHIA. 107 



is only a variety of tricarinata; and it owes its deviation from 

 the usual forms to the influence of station. " V.sincera n is found < 

 in marshes in Michigan. 



Vertigo Bollesiana, Morse. 



On vegetation by roadside, margin of a swamp in Litchfield, 

 1871. Those I have are from Dr. Brown. 



Vertigo milium ? Gould. 



A small species is sometimes found among the drift floated by 

 the rivers at high water in the spring, near Mohawk. 



Vertigo ovata, Say. 



Litchfield, with V. Bollesiana, 1871. It may possibly also 

 occur in the valley; but specimens heretofore regarded as this 

 species were referred by Morse to the following species. 



Vertigo ventricosa, Morse. 



Sometimes found alive in bogs. Oftener found dead in the high- 

 water drift floated into windrows by the river. 



Vitrina limpida, Gould. 



In November and December, 1864, I found immense numbers 

 of large, fine specimens of this Vitrina along the shaded slopes of 

 a ditch on the flats near Mohawk. The soft parts were very dark. 

 Since that time no specimens of Vitrina have been seen near Mo- 

 hawk though repeated search has been made for them. Dr. Brown, 

 of Litchfield, finds Vitrina in his 3"ard. His residence is on a rich 

 soil, the eastern slope of a hill, at an elevation supposed to be 

 about 1260 feet above the sea-level. His specimens are not nu- 

 merous, but are apparently perennial. 1 

 Vivipara contectoides, W. C. Binney. 



A colony (from Illinois) planted in the Erie Canal, fall of 1867, 

 is now thriving. A few specimens were found there in the spring 

 of 1871, remarkable for their beauty and perfect development. 

 Zua lubrica, Leach. 



Stations are numerous, but shells not abundant. 



Mohawk, K Y., Jan. 15, 1872. 



1 Since the preceding notes were written, Dr. Brown lias presented nu- 

 merous large adult specimens taken late in the fall of 1871. The shells are 

 apparently identical with those of the colony of 18G4, but are not so pale 

 being slightly tinged with green. The soft parts of Dr. Brown's speci- 

 mens are not so dark as those found in 1864. Similar variations in color 

 have been observed in the soft parts of well-known species of Succinea. 



