CRUSTACEA. 85 



anterior slope of the glabella is broad and nearly vertical, the occipital fur- 

 row narrow, and the occipital ring broad upon the axis, arched, and bearing 



at its center two long, divergent spines which arc curved downward and 

 slightly inward toward their tips. In the single specimen observed which 

 retains one spine apparently entire, its length is nearly equal to the length 

 of the cephalon. 



Eye-lobes small, inconspicuous. 



Surface bearing tubercles which arc closely disposed over the frontal lobe, 

 but are scattered or obsolescent on the lateral lobes. On the posterior slope 

 of the frontal lobe these tubercles appear to be arranged in two longitudinal 

 rows of three or four each. The spines of the head shield are covered with 

 acute pustules and granules. 



Dimensions. Two individuals afford the following measurements : 



(b) 



Length 13 mm. 6 mm. 



Width between the eyes 14 nun. 8 mm. 



Height .. -. 10mm. 6mm. 



Length of occipital spine 13 mm. 



Distribution. Upper Helderberg group. Corniferous limestone, Schoharie. 

 Schoharie county; in the decomposed chert boulders, Canandaigua, Ontario 

 county. 



Lichas (Ceratolichas) dracon, n. sp. 



PLATE XIX B, FIGS 

 Acldaspis, n. sp. ? Hall. Illustrations of Devonian Fossils, pi. xix, 8gs. 2. 3 [not fig. I I. 1876. 



Two fragmentary Cephala which agree in general features with the preceding 

 species show some important variations, as follows: the frontal margin is more 

 transverse, the marginal sulcus broader, the frontal lobe slightly more elevated 

 and apparently bearing two pairs of strong spines on the posterior edge. Of 

 these two pairs, the stronger have their bases wide apart near the margin of 

 the lobe, and the other shorter pair is situated behind and within the former. 



