199 PALAEONTOLOGY OF NEW- YORK. 



Gekvs Spii.erocystites (n.g.). 



[ Gr. tf^aipa, tphcera; xutfri;, vesicaj] 



Body spheroidal, wider than high. Arms in two principal pairs, with 

 numerous bifurcations. Brachial sulci obliquely lobed. Mouth longitudi- 

 nal ? apicial : anus subapicial ; ovarian opening upon the summit. Basal 

 plates four ; those of the series above not determined. Base depressed. 



Column imknown. 



Tliis fossil, though having the general aspect of Callocystites, or Lepadocrinus, I 

 have characterized as a distinct genus, from the remarkably rotund form, tlie nu- 

 merous branching arms, the position of the ovarian opening upon the summit, and 

 the narrow elongated pectinated rhombs, the two upper of which are remarkable for 

 being upon the summit and having their direction almost precisely at right angles 

 to each other. The whole fossil is silicified; and fi-om this cause, and the numerous 

 ramifications of the arms, the junction of the plates is obliterated; but the depressed 

 spherical form, and the disposition of the rhombs, indicate an essential modification 

 of the plates compared with Lepadocrinus. 



Spliserocystites niultifaseiatus ( n. s.). 



Plate VII A. Fia. 1 - 4. 



Body spheroidal : height or length a little less than the transverse dia- 

 meter ; Jength from anteal to posteal extremity greater than the trans- 

 verse diameter. Base excavated for the reception of the column. Basal 

 plates four : plates of second and higher series unknown. Ovarian 

 apertiure at the summit, midway between apex and margin. Mouth 

 central and longitudinal? Anal pore subapicial, a little upon the left 

 side. Pectinated rhombs extremely narrow and elongated, scarcely dis- 

 similar in form : as many as forty bars may be counted in a single one 

 of these spaces. 



Arms Iil two pairs, composed of small plates lodged in shallow lobed 

 grooves, which are numerously and irregularly divided below till the 

 entire surface is covered by their ramifications. 



Column unknown, but probably similar to that of Lepadocrinus. 



