V. Botryocrinus. 401 



the angles of the lumen. In the proximal region of the stem 

 these sutures do not reach to the exterior and are not always 

 easy to distinguish in section. They are always very obvious 

 in the distal region, and are for example clearly seen on the 

 exterior in E 1412 and E 5611. In E 1412 the sutures can 

 be traced externally to a distance of 70*5 millim. from the 

 distal end, i. e. for about f the length of the stem. In the 

 middle region of the stem the radial sutures are straight, and 

 cut the horizontal sutures at right angles, thus dividing each 

 ossicle into five equal and symmetrical pentameres. But 

 distalwards a change gradually takes place : the radial sutures 

 are no longer straight but zigzag ; the pentameres are bent 

 upwards on one side, downwards on the other ; thus the penta- 

 meres of each ossicle do not exactly register, but partly overlap 

 so as to abut laterally against pentameres of the adjacent 

 ossicles. This semi-alternating disposition of the ossicles is 

 clearly seen both in E 5611 (PI. XIII. fig. 5) and in E 1412 

 (fig. b, p. 408). 



The Root is preserved in E 1412 (fig. 6, p. 408). It there 

 occupies about 6 millim. of the distal end of the stem ; three 

 cirri are seen issuing from one of the radial sutures, and one of 

 them bifurcates once. The longest cirrus is 9'5 millim. long, 

 has a diameter of '9 millim., and is composed of 12 ossicles. 



This species resembles B. ptnnulatus in the shape of its cup 

 and in its pinnulate arms, and in these points it differs from 

 B. ramosus, B. ramosissimus, and B. cucurbitaceus. From B. 

 pinnulatus it differs in the lesser length of the arms, the alter- 

 nation of the sutures between the main arm-ossicles, the 

 greater stoutness of the pinnules, and the more strongly 

 marked ridges of the ventral sac. 



Before leaving this species it is necessary to justify the 

 rejection of Salter's supposed species, Cyathocrinus quindecim- 

 alis. The specimen a/495 in the Woodwardian Museum, to 

 which this name was attached, is figured on PI. XIII. fig. 13. 

 A mere inspection of this figure will show that it has not 

 " fifteen arms," while a comparison of it with fig. 14, which 

 represents one of the specimens labelled by Salter Cyatho- 

 crinus decadactylus, w T ill show that it has not le thicker 

 tentacles." The orientation of this specimen is uncertain ; 

 the cup is much broken and its plates indistinct ; portions of 

 four rays are visible. So far as can be seen these rays bifur- 

 cate on the third or fourth costal, and give off pinnules just 

 as described above. But taking the second ray from the left 

 of the specimen, and directing attention to its right branch, a 

 peculiar pinnule is seen to arise on the outer side of the second 

 brachial. The peculiarity of this pinnule is that it bifurcates 



