'396 Canadian Record of Science. 



a distance about equal to its own breadth from the margin 

 of the convex (ventral) side. 



Black Island, Swampy Harbour, Lake Winnipeg, J. B. 

 Tyrrell, 1889 (four specimens), and D. B. Do wring and 

 L. M. Lambe, 1890 (three specimens). Jack Head Island, 

 Lake Winnipeg, 'Messrs. Dowling and Lambe, 1890 (one 

 specimen), Commissioners or Cranberry Island (one 

 specimen), and Point off Moose Creek, eight miles south- 

 west of Whiteway Point (one specimen), D. B. Dowling, 

 1890. All the specimens from these, localities are mere 

 casts of the interior of the shell, but the septa and 

 siph uncle are usually well preserved. 



This large, elongated, slender and sickle-shaped Cyrto- 

 ceras is so unlike any other species of that genus known 

 to the writer, as to call for no special comparisons. 



EURYSTOMITES PLICATUS. (Sp. 110V.) 



Shell involute, volutions apparently one and a half, 

 coiled closely on the same plane but without embracing, 

 strongly compressed on the venter and dorsum and 

 increasing very slowly in the ventro-clorsal diameter, but 

 expanding and widening rapidly at the sides, which are 

 rounded and gibbous, the outline of a transverse section 

 of the chamber of habitation near the aperture being 

 broadly reniform, with the lateral diameter about three 

 times greater than the dorso-ventral, and the dorsum 

 impressed by a shallow and rather narrow furrow of 

 contact : umbilical perforation large and deep. 



Surface marked with rather broad, low, rounded, 

 nexuous, transverse plications, and crowded striae parallel 

 to the plications, both between and upon them. 



A longitudinal section through the centre of one of the 

 specimens shews that the cut edges of the concave septa 

 are about two millimetres apart on the dorsum, and seven 

 mm. on the venter, near the body chamber, that the 



