334 REPORT ON THE STATE CABINET. 



This specimen measures, from the centre of the disc to the extremities 

 of the rays, about one inch and a half; the widest part of the ray, which 

 is near the margin of the disc, is about an eighth of an inch in diameter. 

 The I'ays towards their extremities, have the ambulacral field covered by 

 the curving of the marginal plates over the groove, and which, closely 

 uniting by their margins, give a teretiform termination of nearly one- 

 third the entire length, each one having the aspect of a slender crinoidean 

 proboscis. 



Geological Formation and Locality. — In the Hamilton group, near Fenner, 

 in Madison county. New York. The specimen was collected during the 

 geological survey, and is now in the State Museum. 



GENUS PTILONASTER, n. g. 



[TTTikoy ^ pcnna ; aarijp^ aster.'\ 



Form and general features as in Eugaster, but differing in the plates of 

 the rays. Foays composed of an ambulacral, adambulacral and 

 marginal series, which are united by their edges, and apparently 

 not imbricating, the projecting or oblique anterior face of the 

 marginal plates bearing spines which are inclined towards the 

 extremity of the ray. Margins of the rays alated by the extension 

 of the disc. 



I had originally united this form with Eugaster, but further examina- 

 tion has shown the ray to have a range of marginal plates outside of the 

 adambulacral plates, and I am unable to discover any such feature in 

 Eugaster logani. 



This and the preceding genus belong to the Ophiuridse, to which may 

 also be referred the Genus Protaster. 



Ptilonaster princeps, n. s. 



' PLATE IX, FIG. 9. 



The specimen consists of the impression of the greater part of one ray, 

 with parts of two others, and intervening portions of the disc. The 

 disc has extended along the ray nearly an inch from the centre of 

 the body ; the plates are small, and have been furnished with 

 slender spinules. The ray is strong and extremely elongate, having 

 been at least four and a half inches in length ; its greatest width is 



