62 CANADIAN MICRO-rALiEONTOLOGY. 



A. FEOM THE CAMBRO-SILURIAN EOCKS. 



1. Aparchites mundulus (sp. nov.) 



Phxte 10, figs. 12 a and b. 



Length 1*13 (hinge-line -6), height '86, thickness of carapace '6, mm. 



Subcircular, with a straight hinge-line [not so long as in the drawing, 

 having been restored too boldly at the broken end], modifying the 

 upper edge of the outline, which, if the curvature were continued, 

 would be a short, broad oval. The free margin is almost symmetri- 

 cally rounded. The surface is smooth and moderately convex. This 

 sublenticular species closely approaches Aparchites decoratus, Jones 

 (Ann. Mag. Nat. Hist., sen (>, vol. IV, 1889, p. 2^2, pi. xv, tig. 12), 

 from the Llandovery beds at Wisby, but it has a relatively longer 

 hinge-line [though not so long as in the tigure] than A. decoratus, no 

 ornament, and rather less convexity. 



I propose to name this neatly formed species Aparchites mundulus. 



One specimen: so much imbedded that at first it was taken for a 

 Folycope, see Quart. Jour. Geol. Soc, vol. XLVJ, ]). 553. From the 

 dark grey, hard Trenton Limestone, with small organisms, at the Falls 

 of Lorette,* on the Eiver St. Charles, Province of Quebec, collected 

 by Mr. H. M. Ami in ]888. A small but obscure allied form occurs 

 also in the same limestone, with Trinucleus concentriciis and Ceraurus 

 pleurexanthemus. 



A similar but smaller specimen, possibly a Polyco})^ is in fine- 

 grained grey limestone (Chazy ?), Quebec City, where it was collected 

 by Mr. H. M. Ami. 



2. Aparchites Tyrrellii (sp. nov.). 



PI. 13, figs. 14 a, U b and c. 

 Length -5 (hinge-line -35), height -32, thickness -17, mm. 



Many minute, suboviform ostracoda, the valves of which arc repre- 

 sented by pyrites, are imbedded in a fine grained sandstone, with a sili- 

 ceous cement. The matrix is grey and the valves dark olive; hence the 

 stone is of a dark grey in colour ; but weathers to a creamy white, the 



^ For notes on the limestones in Quebec and at Lorette, sec the " Gool. and Nat. Hist. Survey 

 of Canada: Second Report on the Geology of a portion of the Province of Quebec." liy R. W. 

 Ells, LL.D., <fcc., 1888. Also, Mr. II. M. Ami's paper in the Bullet. Ueol. Soc. America, vol. II, 

 1891. 



