CRUSTACEA. 
151 
Cheeks broad, depressed about the base of the eyes and sloping with slight 
concavity to the margins. Occipital furrow narrow and deep ; occipital ring 
rounded. 
Eyes small, and elevated above any other portion of the head. 
Surface smooth or minutely punctate. 
The other parts of the animal have not been discovered. 
Dimensions of the cephalon. The single specimen which has been observed 
measures 2 mm. in length and 3.8 mm. in width. 
Observations. This species, in its general features, in the convexity of the fron¬ 
tal area and the smoothness of the test, appears to be closely similar to Cyphaspis 
minuscula. It differs from the latter in its more elevated and wider border and 
shorter cheek-spines, as well as in its smaller size, it being one of the most minute 
species of Cyphaspis yet observed in the Devonian rocks. Its occurrence in the 
beds of the Chemung group makes it the latest known representative of the 
genus, and with the exception of the somewhat doubtful species, Phacbps nupera, 
is the only trilobite known from this formation. 
Distribution. Chemung group. Chemung county. 
Cyphaspis cgelebs, n. sp. 
PLATE XXIV, FIG. 1. 
General Form and Proportions. Outline elliptical, lateral margins rapidly 
curving to the pygidiuni. 
Surface depressed, distinctly trilobate. Axis broad, rapidly tapering 
posteriorly. 
Cephalon semi-elliptical in outline; marginal rim flattened, slightly reflexed; 
produced at the genal angles into spines, which extend to the pygidium. 
Frontal area convex, abruptly deflected from the glabella; lateral area 
depressed-convex. 
Glabella ovoidi', basal lobes distinct. Palpebral lobes high, distant; palpe¬ 
bral sulcus broad and deep. 
