.382 AxNALs OF THE Carxegie Museu.m. 



figure and description only in size. The cephalon figured by Billings 

 from Ottawa is about an inch and a half long, while our specimens 

 vary from an inch to an inch and a quarter in length. 



Descriimion. 



Ceplialon. — (Glabella oblong, strongly convex, tapering toward the 

 front, 'i'he first ])air of glabellar furrows make distinct, rounded 

 lobes, but reach only about half way to the median line. The second 

 and third pairs of furrows are very faint, often not visible. Neck seg- 

 ment narrow and convex. 



Cheeks strongly convex, highest at the eyes, slo])ing abruptly at 

 the sides, but gently in front, where an angle of about 45° is made 

 with the border. Eyes small, situated well forward and rather close 

 to the glabella. 



Border semi- circular in front, about five or six millimeters wide, 

 becoming narrower back on the genal angles, which are prolonged 

 about half the length of the cephalon behind the neck segment. The 

 entire border and cheeks outside the glabella are thickly pitted, a 

 single row of larger pits extending around the outside margin of the 

 border and along the edge of the glabella. A double row of large 

 pits marks the juncture of the convex cheeks with the conca\e border. 

 Glabella and two small oval spaces outside the posterior glabellar 

 lobes smooth, with the excei)tion of a narrow si)ace along the crest of 

 the glabella, which is faintly j)unctate. 



Measiircinenfs. — An average cephalon : length 25 mm.; width 26 

 mm. Anterior margin to neck segment, 13 mm.; glabella 7.5 ram. 

 long ; eyes 7 mm. apart, 1.5 mm. from side of glabella. 



Another specimen is 30 mm. long, 27 ram. wide. 



Locality. — Most abundant in the lower Chazy limestone in the 

 rocks along the lake shore about a mile north of ^"alcour, New York. 

 The figured specimen is in the writer's collection. 



Family TRINUCLEID.K Barrande. 



Genus AM PYX Dalman. 



Subgenus Loxchopomas Angelin. 



Lonchodomas halli Billings. (Plate 10, figures 3-7.) 



Anipyx Ilalli Jjillings, 1861, On some new or little known species of Lower Silurian 

 Fossils from the Potsdam Group. Geological Survey of Canada. Reprinted in 

 volume I, Paleozoic Fossils of Canada, 1865, page 24, figure 25, a-c. 



