71 



OBOLELLA IDA. (N. sp.) 



Fig. 63, a, b. 



Description. Shell small, obtusely ovate, greatest width at or a little 

 in front of the middle, abruptly narrowed to the beaks, sides and front 

 margin uniformly rounded, the front slightly less convex than the sides. 

 Both valves equally and rather strongly convex, most elevated at about 

 one-third the length from the apex, thence sloping with a gentle curve to 

 the sides and front margin, abruptly descending on each side of the beak 

 and umbones. Ventral valve slightly more pointed above than the dorsal ; 

 umbo narrowly convex ; beak apparently depressed to the level of the 

 lateral margin. Dorsal valve obtusely angular or narrowly rounded at 

 the beak, the latter not visibly distinct from the cardinal edge ; umbo 

 obtusely convex. Surface with a somewhat shining aspect, with a very fine 

 concentric striae ; a few radiating striae are visible on two of the specimens. 

 Shell apparently very thin. 



Length of a perfect ventral valve, 2 lines ; width, 1J lines. The length 

 and width of the dorsal valve are about equal. 



This species somewhat resembles a Lingula, but in general its aspect is 

 so much like that of an Obolella^ that although the internal characters have 

 not been observed, I think it best to refer it to the latter genus. It is 

 one-third smaller and not so thick-shelled as 0. chromatica, and differs 

 from that species in having the beaks depressed down to the level of the 

 lateral margin instead of a little elevated. 



It differs from 0. pretiosa in having the umbones more tumid, the beaks 

 not so sharply pointed, in its greater convexity, smaller size, and less pro- 

 portional width. 0. desiderata is larger, and more obtuse in the rostral 

 half. 0. nana (Meek and Hayden) is proportionally broader. 



Locality and Formation. Point Le>is. In limestones Nos. 1 and 3, 

 Quebec group. 



Collector. Sir W. E. Logan, J. Richardson, and R. Bell. 

 LINGULA IRENE. (N. sp.) 



Fig. 64. a, b. 



Description. Nearly circular or very broadly ovate ; beak small and 

 apparently acute ; apical angle about 90. Sides for about one-fourth the 

 length next the beak straight or very nearly so, sometimes slightly concave 

 and occasionally with a barely perceptible convex curve. In the anterior 

 two-thirds, the sides and front margin are uniformly curved so as to give 

 to the front part of the shell a circular contour. Surface with fine but 



