WHiTEAvES.J LARAMIE AND CRETACEOUS INYERTEBRATA. 2.1 



Yalyata filosa. (X. S]^i.) 

 Plate 3, figs. 7 and 7a. 



Shell small, depressed turbinate, spire raised verj- little above tlie 

 highest level of the outer whorl : volutions three, regularly rounded ; 

 suture distinct and deep : umbilicus rather less than one-third of the 

 diameter of the base: aperture circular: outer lip thin and simple. 

 Surface of the outer volutions marked by closely and regularly 

 arranged, transverse and somewhat flexuous thread-like raised lines 

 which are too minute to be visible without the aid of a lens. Test very 

 thin and fragile. 



Maximum breadth, about three millimetres : height considerably less. 

 but not ascertainable with much exactitude, all the specimens having 

 either the ujjper or the under side buried m the matrix. 



Pincher Cieek, T. C. Weston, 1883. St. Mary E. Series : not uncom- 

 mon, but with the delicate test rarely preserved. 



Mouth of the Blind 3Ian Eiver, Township 39, Eange 2T, west of -ith 

 Principal 3Ieridian, J. B. Tyrrell, 18SJ:: from the same beds as Lmncea 

 tenuicostata. 



Some ca^t^ of a small Yalvata from the Xorth or Second Branch of 

 the Milk Eiver, which are referred to Planorbis or Valvata subumbihcata 

 ofMeekikHayden, by Dr. G. M. Dawson, on page 131 of his " Eeport 

 on the Geology and Eesources of the Eegion in the vicinity of the 

 49th Parallel,'' are probably referable to this species. 



This little bhell appears to belong to a well-marked bection of the 

 genus, which ha^ several tertiary as well as recent representatives, and 

 which Fitzinger has proposed to separate under the name Gyrorbis. Its 

 sculpture and shape are not unlike those of the Valvata Leopoldi of 

 De Boissy, from the French Eocene, as figured by Pictet (Traite de 

 Pal(jontologie, atlas, pi. 58, fig. 21), and Chenu (Manuel de Conchylio- 

 logie, vol. 1, fig. 2229), but the Canadian species has much the narrower 

 umbilicus of the two. 



Among recent shells V. filosa is very closely allied to the V. striata 

 of Dr. Lewis, which is common in the Province of Quebec, and which 

 in the writer's judgment, is quite distinct from the V. smcera of Say. 



Valvata bicincta. (N. Sp.) 

 Plat© 3, figs. 8, 8a and 8b. 



Shell depressed turbinate or subdiscoidal, spire raised very little 

 above the highest level of the outer whorl in some specimens, its apex 



