272 PROCEEDINGS OF THE ACADEMY OF 



the eyes than anteriorly ; sides nearly parallel, bnt a little sinuous at the 

 middle ; posterior lateral lobes comparatively large, subtrigonal or tuberculi- 

 form, and entirely isolated by the distinct lateral furrows passing obliquely 

 across with a backward curve, from opposite the middle of each eye, so as to 

 intersect the neck furrow ; second lateral lobes much smaller and more ob- 

 scure than those behind, and also oblique, being merely defined by a faintly 

 impressed, curved, oblique line ; in advance of these there are also obscure 

 indications of two other short, nearly obsolete lateral furrows, scarcely visi- 

 ble without a lens. Occipital segment well defined, but lower, and consider- 

 ably shorter in its transverse diameter than the glabella ; strongly arched up- 

 wards, (not forwards) and projecting backwards a little beyond the posterior 

 line of the cheeks ; neck furrow distinct and arching upward with the occi- 

 pital or neck segment ; its continuation along the posterior sides of the cheeks 

 very deep, and nearly straight for about two-thirds of the way across towards 

 the lateral margins, where it intersects another furrow or depression, coming 

 around the sides of the cheeks. Eyes lunate, rather large, or nearly half as 

 long as the glabella, exclusive of the neck segment, prominent, but not as 

 high as the glabella, located about half their own length in front of the po- 

 sterior margin of the cheeks ; visual surface smooth, or even apparently pol- 

 ished, and showing no traces of lenses under a good magnifier ; palpebral 

 lobes convex, and not depressed, but resting like a lid upon the eyes. Cheeks 

 subtrigonal, declining abruptly from the eyes ; lateral margins turned down- 

 wards, and forming below a sharp edge, which continues back along the lower 

 margin of the posterior spine-like appendages ; above this there is a vertically 

 flattened, or even concave zone or belt, extending from near the front part of 

 the glabella around the outside of each cheek, and becoming a shallow furrow 

 as it passes back upon the spines, along which it seems to be more or less 

 marked nearly to their pointed extremities ; between this vertically flattened 

 band and the eyes, there is another nearly horizontally flattened, or outward 

 sloping zone, extending around each cheek from near the front posteriorly, so 

 as to unite with the lateral continuations of the neck furrow behind, and con- 

 tinue as a single furrow along the upper outer 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 appendages, 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 out- 

 ward from the anterior side of the eyes, and again curving inwards, so as to 

 cut the anterior margin nearly on a line with the anterior inner extremity of 

 the eyes ; from the posterior end of the eyes, directed obliquely outwards and 

 backwards, so as to intersect the posterior margin nearly midway between 

 the neck segment and the subspiniferous lateral posterior appendages. 



Thorax only known from a few of the posterior segments, which show the 

 mesial lobe to be wider and distinctly more prominent than the lateral lobes, 

 which are flattened near the mesial lobe, and abruptly deflected downwards 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 semielliptic, slightly wider than long, and rather convex, dis- 

 tinctly narrower and a little longer than the cephalic shield, narrowing back- 

 wards and very narrowly rounded at the posterior extremity. Mesial lobe 

 prominent, 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 terminating rather abruptly nearly 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 pygidium, but becomes narrower anteriorly ; segments of mesial 

 lobe, eighteen, well defined, rounded and very nearly or quite straight. Late- 



[Dec. 



