253 



Spirifer CRI8PUS 1 Hisinger. Var. 

 Plate 27, fig. 1. 



Shell apparently similar, in size and general shape, to the ;S'. crispus, 

 as described and figured by European and American palseontologists, but 

 with narrow and angular, not broad and rounded ribs. 



Middle rapid : one specimen. 



Spikiper (?) sp. indet. 



Portage road at falls, one specimen ; and foot of portage road, one 

 specimen ; both casts of the interior of ventral valves that arc possibly 

 referable to S. radiatus, Sowerby, but that are much too imperfect and 

 too badly preserved to be satisfactorily determined, even generically. 



Reticularia septentrionalis, Whiteaves. 

 Plate 27, figs. 2, 3, 4 and 5. 



Seticularia septentrionalis, Whitenves 1904. Geol. Surv. Canada, Ann. Rep., 



vol. XIV, pt. F, p. 44. 



" Shell strongly biconvex, but often with a faint, shallow, narrow long- 

 itudinal groove or depression in the median line of each valve ; varying 

 in outline in different specimens from subovate or somewhat pentagonal 

 and a little longer than wide, to not far from circular and as wide as 

 long, but always abruptly contrasted and attenuate in the umbonal region 

 behind ; front margin of the valves straight and entirely devoid of a 

 mesial fold or sinus. 



'' Ventral valve with a narrow but prominent or produced umbo, a 

 depressed, incurved and acute beak, and an extremely small delthyrium. 



"Umbo and beak of the dorsal smaller and less prominent. 



"Most of the specimens are little more than mere casts of the interior of 

 the closed valves. Their surface is entirely devoid of ribs of any kind, 

 and at first sight would seem to be marked only with concentric lines of 

 growth. But, upon closer examination, numerous, obscure, close-set and 

 very slightly raised concentric lines, or faint and minute, low, rounded 

 ridges, can be detected on portions of the exfoliated test that happen to be 

 preserved, and the shell structure, under a lens, is seen to be fibrous. 



" Characters of the interior of the valves unknown, though there are 

 indications of a median septum in each. 



" Lower rapids, one specimen ; middle rapid, one specimen ; and portage 

 road at falls, four specimens. 



"This large and nearly smooth species is provisionally referred to the 

 genus Reticularia on account of its general resemblance to R. modesia 

 (Hall), and R. perplexa (McChesney) which is the Spirifer lineatus of 



