82 THE VOYAGE OF H.M.S. CHALLENGER. 



The first few pinnules have wide basal joints, the fourth and fifth of which are 

 sometimes expanded towards the dorsal side. This is most marked in the larger 

 specimen. The later pinnule-joints are elongated, but very much more slender in the 

 small specimen than in the larger one. The lower pinnules appear to be the longer, 

 containing more numerous, though shorter joints. That on the fourth brachial in the 

 larger specimen is almost 12 mm. long, and consists of twenty-five joints. 



Disk 5 mm. wide. It bears numerous calcareous nodules, but the brachial ambulacra 

 only have delicate rods and networks of limestone at their sides. Saccidi are present, 

 though small, inconspicuous, and few in number Skeleton white. 



The smaller specimen is 3 "2 mm., and the larger 4 "5 mm. across the centro-dorsal. 



Locality— Station 205, November 13, 1874; lat. 16° 42' N., long. 119° 22' E.; 

 1050 fathoms; grey ooze; bottom temperature, 37° F. Two mutilated specimens. 



Remarks. — This is a very singular species. The two mutilated individuals described 

 above resemble one another very closely in the characters of the calyx and arms, while 

 the cirri and pinnules vary considerably. In the smaller one I can find no certain trace 

 of any but the long-jointed cirri like those of Eudiocrinns semperi and Eudiocrinus 

 japonicus (PI. VI. fig. 1 ; PI. VII. figs. 2, 7). 



But in the larger form, which retains the bases of two, if not more of these, the 

 majority of the remaining cirrus-stumps consist of numerous short joints but little longer 

 than wide (PI. VII. figs. 3, 5). 



In the smaller form again, most of the pinnules are quite slender and delicate, with 

 somewhat glassy joints, which are twice, or more than twice, as long as wide (PI. VII. 

 fig. 4). But in the larger one they are usually considerably stouter and more massive, 

 though one or two of the lowest pinnules are much more slender than their fellows, and 

 somewhat resemble those of the smaller individual (PI. VII. fig. 3). This species is at 

 once distinguished from Eudiocrinus semperi and Eudiocrinus japonicus, which resemble 

 it in having an articulation between the first two brachials, by the presence of a pinnule 

 on the second one. 



Eudiocrinus semperi, n. sp. (PL III. fig. 7 ; PL VI. figs. 1-3). 



1882. Eudiocrinus semperi, P. H. Carpenter, Journ. Linn. Soc. Lond. (Zool.), 1882, vol. xvi. p. 497. 

 Centro-dorsal small, nearly hemispherical, or somewhat flattened, thickly covered 

 with cirrus-sockets, except at the dorsal pole. These have strongly marked articular 

 rims around the opening of the central canal, and are from twenty to thirty in number. 

 Cirri probably 30 mm. long, and tapering, of twenty-six joints ; the first three or four 

 quite short, the next more than twice as long as wide, and the four following ones the 

 longest, sometimes exceeding 2 mm. The remainder diminish slowly in size, but exhibit 

 no traces of any dorsal spines. 



