WHITEAVES.] DEVONIAN FOSSILS OF MANITOBA, ETC. 309 



(S.) Cypricardella PRODUCTA. (N. Sp.) 



Plate 40, fig. 8. 



Shell of medium size, elliptic (jvate, about one-third longer than liigh 

 and very inequilateral ; valves compressed convex, moderately inflated, 

 with a faint longitudinal depression immediately above the low, rounded 

 and very indistinctly defined posterior umV)onal slope : anterior side extre- 

 mel}' short, its margin subtruncated almost vertically below the beaks, as 

 far as the lunule extends, then curving rapidly downward and backward 

 into the ventral margin : posterior side much longer than the anterior, its 

 dorsal and ventral margins broadly and gently convex, and its outer ter- 

 mination narrowly rounded in the centre ; umbones compressed and de- 

 pressed : beaks small, incurved and directed forwards, anterior and nearly, 

 if not quite, terminal : lunule narrowly lanceolate in outline : ligamental 

 area or escutcheon narrow, elongated and well defined. 



Surface marked with numerous, close-set and regularly disposed rounded 

 and rib-like concentric plications, which are about equal in breadth to 

 the narrow gi'ooves between them. Hinge dentition and muscular im- 

 pressions unknown. 



^Maximum length of the specimen figured, forty-nine millimetres : great- 

 est height of the same, thirty-two mm. and a half. 



Dawson Bay, Lake Winnipegosis, at the mouth of Steep Rock River, J. 

 B. Tyrrell, 1889 : a mould of the exterior of a left valve, a wax impression 

 of which is figured. 



It is just possible that the shell for which the foregoing name is pro- 

 posed, may prove to be an extreme variety of the preceding species. It 

 seems to most nearly resemble the specimen of C. helHstriaia from the 

 Chemung Group of the State of New York which Professor Hall figures 

 on plate Ixxiv, fig. 5, of volume five, part two (Lamellibranchiata, 2) of 

 the Palaeontology of that state, but in that specimen the beaks are repre- 

 sented as not nearly terminal, the anterior end as considerably produced 

 and the posterior extremity as obliquely truncated above and narrowly 

 rounded below. 



(S.) Cypricardinia planulata (?) Conrad, var. 



Plate 40, fig. 3. 



Cfr. Pttrima plamdata, Conrad. 1842. .Journ. Ac. Nat. Sc. Phil., vol. vm, p. ijl, 



pi. xiii, tig. Vrt. 

 Cyiiriranlmiajjlari-nlala, Hall. 1870. Prelim. Not. Lamellibr., 2, p. 82. 



" " " 1883. Pal. St. N. York, vol. V, pt. 1, Plates and 



Explanations, pi. Ixxix, figs. 1-5. 

 " " " 188.5. lb., Lamellibr., 2, p. 484, pi. Ixxix, figs. lo. 



