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Near the base on each side is a small ovate node separated 

 from the glabella by a distinct furrow. Longitudinal fur- 

 rows moderately deep. Eyes small, very prominent and 

 rounded, situated about one third the length of the head 

 from the posterior margin ; distance from centre to centre 

 equal to the length of the head forward of the occipital fur- 

 row; the lenses not perceptible. Occipital ring narrow, the 

 furrow well marked, becoming less distinct towards the 

 posterior cheek furrows. Cheeks not prominent except an- 

 teriorly. 



Thorax with twelve segments, highly convex, deeply 

 lobed, lobes nearly equal in the anterior portions ; the axial 

 lobe more rapidly tapering posteriorly than the lateral ones, 

 its ambulations curved forwards in the middle. Lateral 

 segments curved a little backwards, the extremities obtuse- 

 ly rounded, somewhat abruptly bent a little nearer the 

 axial extremity, causing an angular ridge along each lateral 

 lobe, each segment marked by a strong longitudinal furrow 

 above the middle. 



Pygidium small, subsemicircular a little arched forward 

 on the anterior border ; axial lobe extending a little more 

 than two thirds the length of the pygidium. rounded at the 

 extremity and marked by one distinct and oue indistinct 

 annulation, which are also seen in the lateral lobes. Sur- 

 face marked by small scattered pustules which are most 

 distinct on the cheeks and segments of the axial lobe. 



Length of an ordinary sized specimen six tenths of an 

 inch ; greatest width of thorax a little more than three 

 tenths ; length of head twenty-three hundredths of an inch ; 

 length of pygidium less than one tenth of an inch. 



This species differs from all others described in the elon- 

 gate form of the head and in the proportions of the body. 



[Trans. iv] 



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