234 



A badly preserved mould of the exterior of the dorsal surface of a 

 nearly entire specimen of a small trilobite, which is also probably refer- 

 able to /. maximus, and which has a short cheek spine at each of the 

 genal angles, was collected near the First Limestone Point on Lake Win- 

 nipeg, north of the Saskatchewan, in a loose piece of limestone, by Mr. 

 J. B. Tyrrell in 1890. The length of this specimen is one inch and three 

 quarters. 



Two doubled up and nearly entire specimens, which are probably refer- 

 able to this species, though no vestige of the genal spines is preserved in 

 either, were collected by Mr. Weston in 1884, one at Big Grindstone 

 Point, Lake Winnipeg, and the other at Dog Head, on that lake. Jn 

 both of these specimens, but especially in the one from Dog Head, the 

 cephalic shield and pygidium are almost triangular in outline, with the 

 apices obtusely pointed, and the sides nearly straight. 



lLLa;NUS Americands, Billings. 



Illcenus Americanus, Billings 1859. Canad. Nat. and Geol., vol. IV., p. 



371. 

 IHwnus taurus, Hall 1861. Geol. Surv. Wiscons. Rep. Progr., p. 



49. 

 Illcenus Americanus, Billings 1865. Geol. Surv. Canada, Pal. Foss., vol, 



I, p. 329, figs. 316, a-d. 



Illcenus taurus, Meek and Worthen 1868. Geol. Surv. Illinois, p. 320, pi. 3, fig. 2, 



Illcenus crassicauda (Hall and D. Dale Owen) 

 Whiteaves 1881. Geol. Surv. Canada, Rep. Progr. 



1879-80, p. 58c. 

 Illa'nus Americanus, Clarke 1894. Lower Silur. Trilob. Minn., p. 714, 



figs. 20-23. 



This is probably the "-lUcKnus crassicauda " of Dr. D. Dale Owen's list 

 of fossils collected at Lower Fort Garry in 1884, and quoted on page 133 

 of this report. Of late years, casts of the interior of the cephalic shield 

 or pygidium of an Illcenus, which agr^e very well with the descriptions 

 and figures of /. Americanus, have been collected at Lower Fort Garry 

 by Dr. E. Bell in 1880, by Mr. Weston in 1884 and by Mr. Dowling in 

 1891, also at East Selkirk by Mr. McGharles in 1884. Similar or more 

 nearly complete specimens were collected at Washow Bay, Lake Winni- 

 peg, by Mr. Weston in 1884, at Little Tamarack Island by Mr. Dowling 

 in 1890 and at Black Bear Island by Messrs. Dowling and Lambe in 

 1890. 



BuMASTUs Trentonensis (Emmons) Clarke. 



Illcenus Trentonensis, Emmons 1842. Geol. N. York, Rep. Second Distr., 



p. 390, fig. 3. 

 Ilhnius Milleri, Billings 1859. Canad. Nat. and Geol., vol. IV., p. 



375, fig. 10. 

 n M .. 1863. Geol. Canada, p. 151, fig. 112. 



