FOSSILS OF THE COAL MKASUKES. 



nearly horizontally flattened, or outwardly sloping /one, 

 extending around each cheek from near the front posteri- 

 orly. so as to unite with the lateral connections of the neck 

 furrow behind, and continue as a single furrow along the 

 upper margin of the posterior spines, thus leaving a more 

 or less defined mesial ridge between these two furrows 

 the entire length of the posterior lateral spiniferous appen- 

 dages. as well as around the cheeks, to near the front of 

 the glabella ; posterior margins of the cheeks, behind the 

 continuations of the neck furrow, very prominent, or form- 

 ing a thickened rim. Facial sutures extending obliquely 

 forward and outward from the anterior side of the eyes, 

 and again curving inwards, so as to cut the anterior mar- 

 gin nearly on a line with the anterior inner extremity of 

 the eyes; from the posterior end of the eyes, directed ob- 

 liquely outward and backwards, so as to intersect the pos- 

 terior margin nearly midway between the neck segment 

 and the sub-spiniferous lateral posterior appendages. 



Thorax only known from a few of the posterior seg- 

 ments, which show the mesial lobe to be wider and dis- 

 tinctly more prominent than the lateral lobes, which are 

 flattened near the mesial lobe, and abruptly deflected down- 

 wards near the middle : segments divided by a furrow near 

 the anterior side from the knee inwards, and flattened in 

 the direction of the axis at the rounded outer extremities. 



Pygidium semi -elliptic, slightly wider than long, and 

 rather convex, distinctly narrower and a little longer than 

 the cephalic shield, narrowing backwards, and narrowly 

 rounded at the posterior extremity. Mesial lobe promi- 

 nent, a little flattened on each side, and narrower than the 

 lateral lobes, from which it is distinctly separated by broad, 

 strong furrows; tapering gradually backwards, and termi- 

 nating rather abruptly near one-third its own length from 

 the posterior margin, so as to leave a broad, nearly flat, or 

 more or less sloping, smooth border, which extends along 

 each side the whole length of the pyiridiuui, but becomes 



79 



