118 PALEONTOLOGY OF NEW-YORK. 



GEKIS BRArillOCRINl S ( n. g.). 

 [ Or. /3pa)(iov, brachium; xpivo;, liiium.] 



Body unknown or none. 



Arms composed of numerous articulations arranged in single consecutive 

 series (or of pentagonal joints in double series ? ). Base of arm rounded, 

 without articulating suriace. Tentacula composed of thickened node- 

 like joints. 



Bradiiocriiius nodosaiius (n.s.). 



Plate V. Fio. 5 - 7 ; and Plate VI. Fia. 1-3. 



Body imknown. 



Arms very long, composed of numerous articulations arranged in single 

 series, very convex exteriorly and flattened or slightly concave on the 

 inner side, very gradually diminishing from the base. Articulations 

 nearly three times as wide as long : from every fourth or fifth, and 

 sometimes from each third joint, originates a tentacle on one side, and 

 one from the next succeeding joint on the opposite, giving them the 

 appearance of being opposite and in pairs. Tentacula composed of 

 thick bead-like joints, which increase in size from the base to the 

 middle, and thence diminish to the extremities. Section of tentacula 

 round, with a linear foramen, and without any appearance of a groove 

 or canal on the inner side. 



Although I have seen no part of a body which could be regarded as belonging 

 to this crinoid, the character of the arms is so peculiar, that I am induced to de- 

 signate the genus from the feature presented in these appendages. The arms are 

 sometimes much elongated, as seen in the si)ecimen, Phite v, fig. 2, whicli is nearly 

 . four inches in length and still far from being entire. There is often nmch irregularity 

 in the distance from each other of the tentacula : in several specimens, they originate 

 at every fifth or sixth plate of the arm; while in one individual, the greater number 

 originate on every third or fourth plate; and in one or two instances, there is only 

 a single intervening plate. I have also noticed that upon the inner side of the arm, 

 the two adjoining plates bearing tentacles on the opposite edges are sometimes 

 anchylosed, presenting the appearance of a single thick plate. 



