A MONOGRAPH OF THE EXISTING CRINOIDS 249 



H. savignii in which IIIBr series may or may not be present. But its more numerous 

 and spiny cirri readily distinguish it from them both. 



One of the two individuals included in Antedon quinduplicava by Carpenter was a 

 mere fragment, which had lost its cirri, disk, and most of its arms. As it was prac- 

 tically useless in this condition, Carpenter made a preparation of its calyx (see beyond, 

 page 250). I examined the type specimen of Carpenter's Antedon quinduplicava in the 

 British Museum and found it to resemble those collected by the Albatross in the 

 Philippines. The outer cirrus segments are slightly carinate dorsally. 



Carpenter's description of Antedon anceps from Challenger station 212 is as follows: 

 The centrodorsal is a low convex disk. The cirri are about XX, 25-35. The segments 

 are tolerably uniform; a few of them are longer than broad, and the later are slightly 

 carinate. The radials are partially visible. The IBri are short and partly united, and 

 there is a more or less distinct tubercle (a synarthrial tubercle) in the middle of their 

 junction with the widely pentagonal IBr 2 (axillaries). The IIBr series, when present, 

 are 4(3+4). The 10 14 arms are 85 mm. long. They consist of about 150 brachials 

 of which the earlier are triangular and much broader than long, their successors be- 

 coming more quadrate and finally almost oblong with a slight tendency to overlap. 

 Syzygies occur between brachials 3+4, from between brachials 9+10 to between 

 brachials 13+14, and distally at intervals of from 3 to 10 (usually from 5 to 8) muscular 

 articulations. The lowest pinnule, whether P D or PI, is considerably smaller than its 

 successor on the same side. In arms that spring direct from the IBr axillary the 

 largest pinnules are P b , P 3 , and P c , which may reach 12 mm. in length and consist of 

 20 smooth segments most of which are longer than broad, the later ones being carinate. 

 On the inner arm borne by a IIBr axillary the largest pinnules are P 2 and P b , though on 

 the outer arms these are little, if at all, larger than PI. But P a is always small. The 

 disk is naked and much incised. Sacculi are very abundant on the disk, arms, and 

 pinnules. The color in alcohol is white with patches or bands of a faded purple, and 

 the perisome darker. 



Gislen examined the type specimen of anceps in the British Museum in 1925. 

 He said that it is a very curious individual. Two of the postradial series are either 

 unbranched or forked after the IBr 2 . He remarked that it is very interesting to notice 

 that PI in both cases occurs to the left, just as in Eudiocrinus. 



Antedon clemens from Challenger station 212 was described by Carpenter as fol- 

 lows: The centrodorsal is hemispherical. The cirri are about XXV, about 30. The 

 segments are tolerably uniform and smooth, the penultimate with a small spine. The 

 radials are not visible. The IBn are slightly united laterally and the IBr 2 (axillaries) 

 are pentagonal. In the single specimen included by Carpenter under this name one 

 postradial series does not divide at all, three possess IBr series, and one has a IIBr 2 

 series. The 11 arms are about 75 mm. long. The arms are smooth, composed of tri- 

 angular brachials, which are much broader than long, the brachials later becoming 

 quadrate. Syzygies occur between brachials 3+4, again from between brachials 9 + 10 

 to between brachials 13 + 14, and distally at intervals of 2-10 (usually 5-7) muscular 

 articulations. 



The first pinnule is 5 mm. long with about 20 segments, which diminish greatly 

 in size after the first five or six. The next pair (P 2 and P b ) are much longer with a 



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