CRUSTACEA. 145 



Glabella pyritbnn, convex ; basal lobes conspicuous, sub-triangular ; baso- 

 lateral sutures strong; antero-lateral impressions inconspicuous. 



Surface ornamented by punctae, which are strongesl on the frontal area 



near the margin. They are also noticeable over the entire surface of the 

 glabella, basal nodes, occipital ring and frontal margin; moderately strong, 

 scattered tubercles are visible on the glabella and over the fixed cheeks. 

 The frontal border also shows faint indications of a single row of low 

 tubercles. 



The differences in this species and Cyphaspis ornata and Phaethonides varicella 

 are enumerated under the description of C. ornata. 



Distribution. Upper Helderberg group. Corniferous limestone: In boulders 

 of decomposed chert, Canandaigua, Ontario county. 



Cyphaspis ornata. 



PLATE XXI, FIG. 1 ; and PLATE XXIV, FIG. 21. 



Phillipsiaf (BracTtymetapi/s ?) ornata. Hall. Illustrations of Devonian Fossils, pi. xxi, fig. I. 1876. 



Phillipxia coronata, Hall. Miller's Cat. Am. Palseoz. Fossils, p. L'21. 1877. 



[?] PhilUpsia coronata ?. Walcott. Mod.. U. S. Gfeol. Surv., vol. viii ; Pal. Eureka Dist., p. 211. l-- s i 



The original of this species consists of a fragment of the intra-sutural portion 

 of the cephalon, and though additional specimens have come under observa- 

 tion the other parts of the animal are still unkown. This portion of the 

 head-shield is small, greatest length and width equal. Anterior outline the 

 arc of a circle, whose center is at the middle of the occipital ring. Frontal 

 area broad, explanate, closely appressed and slightly elevated about the 

 margins of the glabella, thence depressed for about one-half its width and 

 rerlexed at the frontal margin. 



The facial sutures take their origin on the posterior margin near the genal 

 angles, pass obliquely forward and inward over the ocular lobe, thence 

 forward and outward to the anterior margin in the manner normal to the 

 genus. 



Glabella about one-half the length of the cephalon, sub-ovoid, a little ele- 

 vated along the axial line, separated from the frontal area and the ocular 



