186 



PALEONTOLOGY OF NEW-YORK. 



Fig. 1 a. An individual, natural size, with a portion of the column attached. 



Fig. 1 b. The head and arms of another individual. 



Fig. 1 c. The specimen fig. 1 b enlarged : the small plate supporting the arras is not present in 



this specimen, and one of the plates of the second series is divided transversely. 

 Fig. 1 cZ. A figure showing the structure and form of plates. 

 Fig. 1 e. A part of one of the arms enlarged. 

 Fig. 1 /. A portion of the column of 1 a enlarged. 



Position and locality. In the higher part of the Niagara shale at Lockport. 



{Collection of Col. J EWETT.) 



580. 2. HOMOCRINUS CYLINDRICUS (n. sp.). 



Pl. XLI. Fig. 2 a, b, c ; 3 a, b, c. 



Body subcylindricalj and gradually enlarging above ; first and second ranges of plates 

 nearly equal in size ; an intermediate plate inserted on the upper oblique edges of two of the 

 costal plates, which divides the succeeding scapular plate, giving six in the third series ; 

 arms ? ; column comparatively very strong, composed of alternating thicker and thinner joints, 

 the thicker ones projecting and rounded on the edges. 



The specimen figured is very imperfect, the body and a small portion of the column alone 

 remaining ; the arms are also broken off. All that remains, however, shows the simple struc- 

 ture of the genus, with the plain unornamented surface of the plates. 



Fig. 2 a. The body and part of the column, natural size. 



Fig. 2 b. An enlarged portion of the column. 



Fig. 2 c. The structure, showing the single intercalated plate, and the division of the succeeding 



scapular plate. 

 Fig. 3 a. The body of an individual somewhat more rotund than the preceding, showing the 



same general structure. 

 Fig. 3 b. The base of the specimen which has one of the larger joints adhering, showing the 



central articulating portion, while the outer portion of the face is smooth. 

 Fig. 3 c. A figure showing the structure of the specimen. 



Position and locality. In the central and lower part of the shale at Lockport. 



{Collection of Col. Jewett.) 



