PALEONTOLOGIC CONTRIBUTIONS QI 



widest part. The axis is broad (10 mm) and prominent in its 

 anterior half, contracted and tapering and flat in its posterior half. 

 It bulges in the middle where the contraction of the margins begins. 

 The first annulation is partly broken, but apparently reached trans- 

 versally across ; the second groove is convex and angular backward 

 and does not extend to the lateral grooves. The pleura are nearly 

 flat, sloping a little outward; they are hooklike, curved backward, 

 terminating apparently in rather blunt lobes. The four anterior 

 pleura are each subdivided by a secondary short groove that 

 extends about one-third the length of the pleuron. The surface is 

 ornamented with small tubercles and bears the bases of many spines 

 which are especially large in the last pair of pleura. 



Notes. This species differs from A. trentonensis Hall 

 in the entirely different outline of the middle lobe of the glabella, 

 which in the former is widest behind, and in the latter broadens 

 forward. In this character A. conifrons diverges somewhat 

 from the typical Amphilichas. Also the pygidium of the 

 Trenton congener is different, mainly in possessing a longer axis 

 and straight transversal annulations. 



While the pygidium of our species is very similar to that of 

 the smaller A. minganensis from the Chazy beds, the 

 glabellas differ in the outlines of the middle lobe, as mentioned 

 before. Considering the variability of the lichads, the forms are 

 still sufficiently similar to make it possible that both are genetically 

 directly connected, especially since the more stabile pygidia are 

 so much alike. 



The writer is not aware of any European species of Lichas to 

 which our type approaches, and it also differs considerably from 

 the congeners and the genotype of Amphilichas in the posterior 

 widening of the middle lobe of the glabella and the forward 

 position of the side lobes. In the shape of the middle lobe, and 

 notably also its convexity, and the side lobes, it bears, however a 

 general resemblance to Lichas (Metopias) hiibneri 1 

 Eichwald, and it is conceivable that a similar species of Metopias 

 might lead, through an extension of the first pair of glabellar fur- 

 rows, to our Amphilichas. This is the more probable since Ray- 

 mond 2 has observed that in the young of Amphilichas 



1 See Fr. Schmidt : Revision der ostbaltischen Trilobiten. Abtheilung 2, 

 1885, pi. 1, figs. 13-14, in Mem. de l'Acad. Imp. des Sciences de St Peters- 

 bourg, 7 ser., t. 23, no. 1. 



2 Percy E. Raymond : Notes on Ordovician Trilobites IV. Annals of the 

 Carnegie Museum, v. 7, no. 1, p. 73- if?™- 



