72 Annals of the Carnegie Museum. 



those of B. indetenninatiis, and the genal angles of the latter species are 

 rounded, while the free cheeks of the former are drawn out into broad 

 spines. 



Family LICHADID^ Barrande. 



Genus Lichas Dalman. 

 Subgenus Amphilichas Raymond. 

 Amphilichas minganensis (Billings). 



Plate XVIII, figure 6; Plate XIX, figures 13, 14. 



The name Platymetopus given to this subgenus by Angelin being pre- 

 occupied, Professor Reed suggested Paralichas to replace it. That name 

 also having been used previously, the writer suggested Amphilichas.^ 



Among the specimens collected by Professor Perkins on Isle La Motte 

 is one retaining one of the eyes. The eye is large, and the visual area 

 occupies a semi-circle, giving a large range of vision. 



It is to be noted that all the pygidia so far found in the Chazy are of 

 the type with two complete rings on the axial lobe, three pairs of pleural 

 segments with free ends, and a pointed, triangular axial lobe. Similar 

 pygidia found in Russia are assigned by Schmidt to Mctalichas cicairicosus, 

 while the pygidium assigned by him to Amphilichas lineatus does not have 

 a pointed axial lobe and the two median pleural segments are more or less 

 coalesced. It can hardly be doubted that the cranidia and pygidia found 

 associated in the Chazy belong to the same genus and species, and it is 

 equally unlikely that Schmidt was mistaken in associating the cranidia 

 and pygidia which he referred to A. lineatus. The glabella of Amphilichas 

 is one which might have been developed along parallel lines in different 

 sections of the Lichadidce, and it is therefore possible that our American 

 species is not congeneric with Amphilichas lineatus. Reed finds an as- 

 sociation of parts in Lichas hibernicus Portlock similar to that in the 

 American species, and, following Schmidt, he at one time referred the 

 thorax and pygidium originally described by Portlock to Metalichas, and 

 the associated cranidia to a new species of Amphilichas.^ In a more recent 

 paper, however, he returns to the older association, and refers both parts 

 to Amphilichas.^ 



From the locality at McCu Hough's sugar-bush which has proved so 

 prolific in small trilobites a number of small specimens of an Amphilichas 

 have been obtained. On account of their uniformly small size it is 



^American Journal of Science, Series 4, XIX, 1905, 377. 

 ^Quarterly Journal Geological Society London, LVIII, 1902, 74. 

 ^ P aleonlo graphical Society, 1906, 106. 



