324 PROCEEDINGS OF THE ACADEMY OF [1881. 



the second hexagonal, almost as high as wide ; the third axillary, 

 but smaller hy half or more than the second, sometimes forming 

 a part of the arm-like appendages, which in other species begin 

 with the secondary radials. The secondary radials consist of 

 1X2X5 plates in each ray ; sometimes both are axillary, and 

 as such divide the ray into two equal sections, of which each one 

 forms a separate tube, and gives off lateral arms from either side ; 

 in other cases only one is a bifurcating plate, which is the larger 

 of the two, resting upon the wider side of the primary radials, 

 while the other, which is smaller and obliquely given off, is 

 truncate above, and supports an arm. 



In the same manner other series of radials are given off from 

 all succeeding radial plates, on one side a bifurcating plate bear- 

 ing a higher order of radials, on the other a lateral arm, and this 

 alternately from opposite sides (PI. 18, fig. 3). The number of 

 radials is to some extent indefinite, they extend to almost the 

 height of the arras, which are long, and the ray itself terminates 

 finally in a short arm. All the radials are of the same form, and 

 nearl}'- the same size, decreasing very gradually in an upward 

 direction. They are wider than high, cuneate and alternately 

 arranged, with the shorter side abutting against the side of the 

 preceding arm, while the next arm is given off from the upper 

 oblique side. 



Arms long, of moderate thickness, constructed like those of 

 Actinocrinus, beginning with one or two cuneate pieces, which 

 soon turn into two series of alternate plates. Arm grooves deep ; 

 pinnules unknown. 



Interradials three or more, those of the calyx forming a con- 

 nection with the interradial plates in the dome. The posterior 

 side, like that of all other Actinocrinites, consisting of a single 

 special anal plate, which is in line with — and has the size of —the 

 first radials; it supports two plates in the second, and generally 

 three in the third series. 



Yault highly elevated to moderately convex, composed of a 

 variable number of pieces ; centre and proximal dome plates not 

 distinctly defined. The first radial dome plates, from which the 

 brachial appendages begin, are spiniferous, and so alternately is 

 one-half of the succeeding plates which cover the free rays. 

 The covering of these appendages consists of (two rows of plates, 

 side by side, a larger and a smaller one, which are so arranged 



