I I I PALEONTOLOGY OF NEW YORK. 



Distribution. Upper Helderberg group. From the decomposed chert boulders 

 of the Corniferous limestone: Canandaigua and East Bloomfield, Ontario 

 county. 



Cyphaspis diadema, n. sp. 



PLATE XXIV, FIG. 13. 



A single example of this species showing only the intra-sutural portion of the 

 cephalon has been observed. 



Cephalon minute; length and width equal; curve of the anterior margin an 

 arc with its center at the middle of the occipital annulation ; frontal area 

 broad, gently convex and slightly appressed about the glabellar margins, 

 depressed medially and reflexed upward to the marginal rim. 



Facial Sutures normal. 



Glabella one-half the length of the cephalon, elongate, sub-elliptical ; basal 

 lobes obscure ; antero-lateral impressions discernible. Palpebral lobes prom- 

 inent. 



Surface minutely pustulose upon the glabella, the palpebral lobes and on 

 the frontal area close to the glabella. About half way from the anterior 

 extremity of the glabella to the frontal margin is a single row of minute but 

 isolated and distinct tubercles, parallel to the frontal margin. This feature 

 is characteristic and will serve to distinguish the species. 



Dimensions. The single specimen has the following size : length 1.7 mm., 

 width 2 mm. 



Distribution. Upper Helderberg group. Corniferous limestone : From the 

 boulders of decomposed chert, Canandaigua, Ontario county. 



Cyphaspis hybrida, n. sp. 



PLATE XXIV, FIG. 14. 



Intra-sutural portion of the cephalon only observed. Outline regularly 

 arcuate; length ;md width equal; frontal area concave, elevated at the 

 margin to nearly the height of the glabella. Border broad, thickened. 

 Facial Sutures normal. 



