PART 5 A MONOGRAPH OF THE EXISTING CRINOIDS 541 



Description [modified by A.M.C.]. — The centrodorsal is conical, 3.3 mm. in basal 

 diameter and 2.1 mm. in vertical height, bearing about 35 cirrus sockets according to 

 Carpenter [but having drawn the holotype, I put the number as 9 or 10 in each radial 

 area, a total of about 45. A.M.C.]. The interradial cirri are iu distinct vertical columns 

 but the radial ones are more irregular in position (see fig. 29, p. 539). 



The cirri had 25 to 30 segments (all the peripheral ones are now broken, 1957). 

 The earlier segments are half again as long as broad, and the distal are broader than 

 long with slight dorsal keels. 



The radials are very short. The IBri are short, about four times as broad as long, 

 with slightly converging sides and but little excavated on the distal border. The 

 IBr2 (axillaries) are broadly rhombic, broader than long. These ossicles are flared at 

 the distal edges and bear a few very fine spines, but these are so small as to be only 

 visible under high magnification. 



The 10 arms are about 35 mm. long, but all but two have not quite finished 

 regenerating from the first syzygy and these two are broken at the seventh brachial. 

 The first brachials are nearly oblong, and the second are relatively short and broad 

 with a very obtuse pro.ximal angle. The next few brachials are oblong, and the following 

 become more wedge-shaped and finally cylindrical with slight lateral projections for 

 the pinnule facets. The distal border of each brachial bears a small fringe of spines 

 which projects forward over the base of its successor so as to give the arms a somewhat 

 serrate appearance. 



Syzygies occur between brachials 3 + 4, 7 + 8 or 9+10, and distally at rather 

 irregular intervals, though they are generally separated by three or four muscular 

 articulations. The length from the proximal edge of the IBri to the second syzygy 

 was probably about 8.5 mm. and the width at the first syzygy is 1.25 mm. 



P, consists of 12 or 13 segments, of which the first tliree or four are short but 

 the following ones become elongated; it measures about 4.5 mm.; P2 is shorter, about 

 3.5 mm. long, with about 11 segments, which become elongated after the first two. 

 On the arms which are not regenerating Pj bears a gonad. The following pinnules 

 are at first a little shorter and more slender than the first two but have relatively 

 longer segments, after which the length gradually increases. 



Notes. — Dr. D. Dilwyn John reexamined Carpenter's type specimen and added 

 the following notes. The cirrus sockets are arranged in about 15 irregular columns; 

 these are least regular near the proximal edge of the centrodorsal, around which there 

 are about 20 sockets. The cirri are about XXXV, 25-30; the distal segments from 

 about the tenth outward have a rounded dorsal keel, stronger than that of E. Jraseri, 

 which is not shown in Carpenter's figure. P, is long, stifl", and slender, 4.5 mn\. long, 

 with 12 evenly tapering segments, of which the first two are heavy and broader than 

 long, the third and fourth are about as long as broad, and the remainder are elongated 

 and become more and more slender to the tip of the pinnule; the distal edges of the 

 segments are thorny. Pt is about 4 mm. long, with 11 segments. Carpenter described 

 it as carrjang a gonad, but Dr. John says that if it is a gonad it is very small. The 

 remaining pinnules arise from regenerating brachials and do not carry gonads. 



Locality. — Challenger station 145; near Marion Island (lat. 46°43'00" S., long. 

 38°04'30" E.); 256 meters; volcanic sand; December 27, 1873 (P. H. Carpenter, 1888; 

 A. H. Clark, 1913; John, 1938] (1, B.M.). 



