CRUSTACEA. 57 



The facial sutures take their origin at points on the margins nearly one- 

 half the distance from the genal angle to the anterior border, and follow a 

 direction normal tor the genus. 



Glabella convex, scarcely elevated along the axial line. Width on the 

 frontal lobe about one-third that of the cephalon, rapidly diminishing to the 

 occipital ring. Frontal lobe transverse, sub-rhomboidal ; firsl glabellar fur- 

 rows extending backward, each somewhat less in length than one-third the 

 width of the glabella; second and third furrows transverse, short, not encroach- 

 ing upon the mesial elevation of the glabella; first pair of glabellar lobes 

 sub-triangular, second and third pairs smaller, sub-quadrate. Occipital furrow 

 shallow, widening on the cheeks, and uniting at the genal angles with the 

 marginal sulcus. Occipital ring conspicuous. 



Cheeks depressed at the margin, elevated toward the ocular lobes. 



Eyes anterior, elevated and relatively large. 



Surface finely pustulose except upon the border and occipital ring. 

 The lateral margins and genal spines bear a series of denticulations or short 

 spinules, which, in one specimen, appear to exist also upon the anterior 

 border. The occipital ring bears a strong central tubercle. 



Dimensions. The two specimens of this species which have been observed 

 have about the same size, namely : 



Length 1.7 mm. 



Length to apex of spines 3 mm. 



Width 2.5 mm. 



Observations. This little species bears a striking resemblance in its propor- 

 tions and outline, incurved cheek spines and denticulated bolder to Dalmanites 

 regalis of the Schoharie grit; in the former, however, the eyes are placed 

 further forward, the glabellar lobes are relatively much smaller and the marginal 

 denticulations narrower and pointed. The minute size of the specimens may 

 indicate that they are the young of some species of whose mature form we are 

 still ignorant, but as the only examples yet seen have the same size, it is 

 probable they are of mature growth. 



