352 REPORT ON THE STATE CABINET. 



mouth, and curving spirally outwards and downwards over the 

 body, reaching to or even below the point of its greatest diameter. 

 The central aperture appears to have been closed by a pyramid of 

 five or six small plates. 



The fossils of this genus are remarkable for their elongate form, attenuate 

 base and swelling upper extremity ; they were probably supported upon a 

 short pedicel, but we do not know its character. The body is composed 

 of numerous ranges of short hexagonal or polygonal plates, the spiral 

 arrangement of which can be traced in their marking upon the cast. 



In a fragment of one of these from the Niagara shale of New York, 

 there is but a single subcentral opening visible, the arms all originating 

 on one side of this. In the casts of other species from Wisconsin, there 

 is evidence of a smaller aperture near the round subcentral one. 



A large proportion of the specimens observed are unsymmetrical in 

 greater or less degree, and this feature is apparently very variable in the 

 same species. In a view of the summit, the position of the apertures 

 and disposition of the arms resemble Agelacrinus, but the plates are of 

 different character, being strongly granulose, and the sutures of the plates 

 are so close as to make it difficult to distinguish them. 



GOMPHOCYSTITES TENAX, N. S. 

 PLATE XII, FIG. 15, AND PLATE XII a, FIGS. 7, 2. 



Upper part of body ventricose, somewhat rapidly attenuated below ; 

 principal aperture round, subcentral ; the pyramid of plates which 

 probably closed the orifice are unknown, leaving a margin of small 

 unequal plates. The plates forming the summit of the body are 

 small, polygonal, with surface strongly granulose. The arm-plates 

 appear to have been furnished with tentacula, as in Apioctstites 

 and other genera. 



Formation and Locality. — This species occurs in the Niagara group at 

 Lockport, New York. Collection of Col. E. Jewett.* 



GOMPHOCTSTITES GLANS, N. S. 

 PLATE XII, FIG. 14, AND PLATE XII a, FIGS, i AND 5. 



Body elongate, clavate, with the upper extremity extremely ventricose, 

 often more or less unsymmetrical, and the summit unequally convex 

 on the upper side, somewhat abruptly contracted below, and thence 



* Now in the collection of the Cornell University. 



