Trilobites of ihf Chazv Llmes'jonk. 331 



running a little forward and inward to the front of the glabella. Out- 

 side the eyes are two raised lines running backward and outward down 

 the steep slopes of the cheeks, nearly to the concave border. The 

 cheeks are much steei)er both at the sides and in front, than in Ifarpina 

 othiioarnsis, and the glabella is more convex and more distinctly out- 

 lined. On the front, below each eye, is a depression starting from 

 the front of the glabella and running backward around the middle of 

 the slo|)e of the cheeks. 



The whole surface of the cheeks and border is thickly pitted, as is 

 the top of the glabella, while the sides of the glabella and its lobes 

 are smooth. 



The neck ring is narrow and shows a median pustule. 



A small specimen, 3 mm. long and 3.65 mm. wide, differs from the 

 adult in being proportionally wider and in having the anterior end 

 of the glabella and the ocelli relatively further forward. The border 

 is nearly flat instead of concave, and the glabella shows traces of a 

 second pair of furrows. 



The following measurements show the proportions of the various 

 parts. An average adult. Cephalon: length 8 mm.; width 9 mm.; 

 from front to posterior margin of neck ring, 5 mm.; length of glabella 

 3.5 mm. Distance of eyes from glabella 1.25 mm. ; eyes 3.75 mm. 

 apart. 



Smallest specimen. Cephalon : length 3 mm. ; width 3.65 mm. 

 Front margin to neck ring i.S mm.; glabella 1.3 mm. long; eyes i 

 mm. a|)art. 



Largest specimen. Cephalon; length 15.5 mm.; width 14.5 mm. 



Locality. — This species is common in the lower limestones at 

 Valcour, Valcour Island, and Chazy, New York, and occasionally 

 occurs in the middle Chazy. 



Harpina ottawaensis Billings. (Plate 10, figure 2.) 



Harpes OUiuoaiJnsis IJillings, 1865, Paleozoic Fossils Canada, Volume I, page 183, 



figure 166. 

 Harpina, cf. Harpes otla'Luensis Clarke, 1897, Paleontology Minnesota, Volume 3, 



part 2, page 757, figure 79. 

 Harpma otlawensis\<!^\\&x, 1902, Paleontology New Jersey, \"olunie III, page 191, 



plate XIV, figures i, 2. 



Although the type specimens of this trilobite were obtained from 

 the Trenton limestone, the Chazy specimens differ from the original 



