28 THE NAUTILUS. 



Through the kindness of Dr. Whiteaves I have been enabled to 

 examine some of the Anticosti shells referred to by Dr. Dall. Com- 

 pared with the High Island specimens, these (figs. 4-6) are thinner* 

 less heavily striated, with a rather wider umbilicus, and the body 

 whorl is less inflated, but they evidently belong to the same species. 



As above defined, V. sincera appears to be a less abundant species 

 than lewisii, but of considerable range, though apparently rather local 

 in its habitats. Specimens have been examined from the following 

 localities, in addition to those above mentioned : River Rouge, Wayne 

 county ; Mill Lake, Lake county and Lake Michigan, off New York 

 Point, Charlevoix county, Michigan ; Pigeon Lake, Ontario and 

 Milwaukee, Wis. Some immature specimens from Lake George, 

 N. Y., should also probably be included. It has also been found in 

 the marl deposits at Cement City, Jackson county; Ann Arbor; 

 Monitor, Bay county, and Pine Lake, Charlevoix county, Michigan, 

 and Caribou, Me. As all the marl specimen s are decorticated, it is 

 impossible to say whether they were originally typical sincera or var. 

 nylanderi. 



V. SINCERA NTLANDERI Dall. PI. I, figS. 7-9. 



Judging from the suite examined, nylanderi (figs. 7 and 8) in its 

 original locality is a well marked constant form, and standing alone 

 might well be accorded specific rank. But as stated above, the 

 specimens from High Island Harbor, show decided tendency to ac- 

 centuate the stria?, and in a considerable number from Isle Royale, 

 Lake Superior (collection of 1905), where typical sincera is not 

 represented, all the gradations from close, elevated ribs to the wide 

 spaced lamellae of typical nylanderi are represented. So that there 

 would seem to be no question, but that it is to be considered as a 

 varietal form of Say's species. This form in its various aspects has 

 also been found in Cliff river and Pine Lake, Marquette county, 

 Michigan ; Little Lakes, N. Y., and Lake Geneva, Wis. An un- 

 usually elevated example from Isle Royale, is illustrated by fig. 9. 



V. SINCERA DANIELSI, n. v. PI. I, figs. 10 and 11. 



Shell larger and proportionately higher than the typical form ; 

 whorls 4, finely and regularly striate, very convex with a deeply im- 

 pressed suture. Aperture entire, scarcely appressed to the body 

 whorl. 



Alt. 6, diam. 5.75 mm. 



