266 Canadian Record of Science. 



genus in describing the fauna of Liau-tung in China, and 

 Prof. Meneghini has followed his example. Anomocare is 

 a genus full of interest in connection with the question 

 of the point at which the limit of the Cambrian system 

 shall be drawn. It is a genus which foreshadows the swarm 

 of Asaphoid trilo bites which appeared in the Ordovician 

 seas. This is apparent when (taking A. nomocare limba- 

 tum as the type) we observe in the head shield the 

 narrow cylindrical glabella, the sinuous suture, and the 

 sharp posterior angles of the cheeks; in the thorax the few 

 compact segments ; in the pygidium the prominent narrow 

 many-jointed rachis and the flattened border. 1 Many trilo- 

 bites of the Upper Cambrian beds have been referred to 

 Anomocare, mostly from the head shields, so that it is at 

 present difficult to draw the line between it and Ptychoparia 

 when only these imperfect remains are to be had. Still the 

 presence of these numerous species with flattened borders 

 is a distinctive mark of the Upper Cambrian. 



Neither of the two asaphoid forms of Sardinia, described 

 by Meneghini, agr 3 altogether with the definition of the 

 genera (Platypeltis and Psilocephalus) to which they are pro- 

 visionally referred. In the possession of extended genal 

 points to the movable cheeks they differ from the types of 

 the genera above named and approach more closely to Asa- 

 phus, proper. 2 Asaphus {Platypeltis f) Meneghinii also has 

 a pygidium with several distinct lateral costa and with 

 three marginal points, thus differing from the type. These 



1 It may be thought by some that the presence in Anomocare of 

 a long eyelobe, is an objection to a comparison of this genus with 

 Asaph us-like trilobites, all of which have short eyelobes ; but there 

 is as great variety between the species of Paradoxides in this re- 

 spect as between the two genera named above. In Paradoxides 

 the shortening of the eyelobe is progressive with age both as re- 

 gards the individuals of a species, and as the species appeared suc- 

 cessively in time, and the same may hold good for Anomocare and 

 Asaphus. 



2 Meneghini refers these cheeks doubtfully to the heads of the 

 species described, but the reference to Platypeltis Meneghinii is pro- 

 bably correct. 



