FOSSILS OF THE COAL MKASHiKS. (J13 



behind, with posterior lateral angles produced backwards 

 into rather stout, carinated, pointed spines, which extend 

 as far hack as the fifth thoracic segment. Grlabella broadly 

 rounded and sloping in front, where it is without a pro- 

 jecting marginal rim; distinctly contracted posteriorly, in 

 which region it is most elevated; separated from the cheeks 

 on each side by its much greater convexity, and a shallow 

 furrow, which becomes obsolete around the front ;. posterior 

 lateral lobes comparatively large, subtrigonal, very oblique, 

 depressed, and isolated by the strongly defined lateral fur- 

 rows in front of them being so very oblique and produced 

 as to intersect the neck furrow; midway between these two 

 lobes there is a more prominent mesial node, isolated by 

 an accessory furrow passing across in front of it, so as to 

 cut it oif, as it were, from the narrow posterior central part 

 of the glabella ; second and third lateral lobes very small, 

 transverse, and obscurely defined by short, nearly obsolete 

 linear furrows; anterior lobe larger than all the remaining 

 portions of the glabella between it and the neck furrow. 

 Xeck segment a little higher in the middle (where it is 

 provided with a minute tubercle) than the glabella, strongly 

 arched upwards (not forward), and more than twice as wide, 

 antero -posteriorly as one of the thoracic segments; neck fur- 

 row deep, broad, and arched with the neck segment. Eyes 

 comparatively large, or half as long and (behind) nearly as 

 prominent as any part of the glabella, located with their 

 posterior margins opposite the neck furrow, and less than 

 half their own length in advance of the posterior margins 

 of the cheeks, visual surface yentricose, or subhemisphe- 

 rical, smooth, or even polished, as seen under a good pocket 

 lens, but when examined by a high magnifying power, 

 showing numerous, regularly disposed, minute lenses be- 

 neath the smooth, transparent outer crust; palpebral lobes 

 semicircular, convex, and resting upon the eyes like lids. 

 ( 'hecks, as compared with the size of the eyes and glabella, 

 small, sloping abruptly from the eyes into the deep, broad, 



