122 The Ottawa Naturalist. . [January 



Pholadomorpha pholadiformis (Hall), originally described and 

 figured from this locality (Rept. on Geol. of Lake Superior Land 

 District, 1851, page 213, pi. 30, figs. 1 a-c; pi. 31, fig. 1). Here it is 

 associated with a species of Modiolopsis curved as in Modiolopsis 

 concentrica Hall and Whitfield, but erroneously regarded by Hall as 

 identical with Modiolopsis modiolaris (Conrad), from the Lorraine 

 of New York, a form having a relatively straight hinge-line. This 

 form from the Richmond of Little Bay de Noquette is much larger 

 than typical Modiolopsis concentrica and probably represents a dis- 

 tinct species. It is more or less abundant in the Lorraine-like strata 

 which form the lower part of the Richmond section in various parts 

 of Manitoulin Island, on the southern shores of Georgian Bay, and 

 north of the western half of Lake Ontario. Among other specimens 

 of Modiolopsis found associated with Pholadomorpho pholadiformts 

 occurred a specimen, apparently shortened by pressure (Fig. 21), 

 whose affinities for the present must remain in doubt. 



The species of Archinacella occurring in the cherty Richmond 

 (Figs. 16, A, B), is more circular in outline and more distinctly 

 elevated toward the beak than in Archinacella richmondensis Ulrich, 

 from the Whitewater member of the Richmond in Indiana; moreover 

 the concentric striations are rather fine and not distinctly delimited at 

 equidistant intervals. The general appearance of the shell is smooth. 

 Similar specimens occur in the cherty Richmond two miles southwest 

 of Kagawong, on the road to Gore Bay, on Manitoulin Island, 

 Ontario. The shell is regarded as a new species, Archinacella 

 kagawongensis, the specimens from Manitoulin Island forming the 

 types. 



In the same cherty Richmond, on the eastern shore of Little Bay 

 de Noquette, occurs Cyrtolites ornatus, Conrad, a form of Hormotoma 

 gracilis (Hall), Lophospira bicincta (Hall), Helicotoma brocki, 

 Foerste, and a species of Conularia. The Hormotoma, Fig. 17, is a 

 thick-shelled form; and is notable chiefly for its size. The Lophospira, 

 Fig. 18, has a more angular peripheral and upper carina than the 

 enlarged figure suggests, but there is no evidence of a trilineate peri- 

 pheral band and the lower volution is distinctly convex for some 

 distance below the lower carina. No fourth carina is present. 



Helicotoma brocki, Foerste (Bull. Sci. Lab. Denison Univ., vol. 

 17, 1912) is common and attains a width of 18 millimeters. The 

 only fragment of Conularia found evidently belongs to some fairly 

 large species, and may be identical with Contdaria formosa, Miller 

 and Dver, from the Richmond and Maysville groups of Indiana and 

 Ohio. ' 



A single specimen of a species of Orthoceras (Fig. 19) resembling 

 Orthoceras amplicameratum Hall, from the Trenton of New York, in 

 its rate of expansion and in the ratio of the distance between the septa 



