Poi7it Levi Fossils, 315 



like that of Dilcelocepkalns granulosus. (Owen). [See Geo. 

 Rep. Wisconsin, PI. 1, Fig. 7.] 

 Limestone No. 1, not common. 



Arionellus subclavatus. N. s. 

 Fig. 15, — a. 



Description. — Glabella as long as the head, separated from the 

 front margin by a narrow groove only, strongly convex, and ele- 

 vated in the anterior two-thirds, less convex, more depressed, and 

 somewhat narrower in the posterior third ; sides gently convex, 

 nearly straight, siib-parrallel, slightly more distant from each 

 other towards the front than behind, front obtusely rounded. The 

 neck segment and furrow are rounded and well defined all across; 

 the posterior glabellar furrows are rather strong, directed for- 

 wards at an angle somewhat less than 45°, their inner extremi- 

 ties separated by one-third the width of the glabella, and distant 

 from the neck furrow about the width of the neck segment. In 

 front of these are two obscure, nearly vertical furrows on 

 each side, at about equal distances from each other. The fixed 

 cheeks are strongly elevated, and separated from the glabella by 

 the deep, narrow dorsal furrows. The eyes are small, and situa- 

 ted on a line drawn across the head, passing about midway be- 

 tween the two posterior glabellar furrows. They are connected 

 with the front lobes of the glabella, by slender ocular ridges, as 

 in the genus Conocephalites. The distance of the eye from the gla- 

 bella, is a little more than half the width of the neck segment* 

 The facial suture cuts the front margin, a little inside of a line 

 drawn through the eye, parallel with the length of the body. 

 Behind the eye it runs obliquely outward with a gentle curve, 

 and cuts the posterior margin at a point between the line pass- 

 ing through the eye, and the posterior angles of the head. The 

 surface in the large specimens is finely tubercular, but in the 

 small ones apparently smooth. Length of largest head seen five 

 lines and a half; the width of the glabella at one-third the length 

 from the front, is about three-fourths of its own length, exclud- 

 ing the neck segment and furrow. Moveable cheeks, thorax and 

 pygidium unknown. 



Limestone No. 1. 



