A MONOGRAPH OF THE EXISTING CRINOIDS 129 



Diagnostic features. — P2 is noticeably longer and stouter than P3 and the pinnules 

 following; the cirri are of moderate length and moderately slender, and arc composed 

 of 29-40 (usually 30-35) segments of which the longest are slightly longer than broad; 

 the arms are 40-105 (usually 45-80) mm. long. This is a medium-sized or rather 

 small and rather spiny species. 



Description.— The ckri arc XVIII-XXII, 29-40 (usually about 35), 25 to 30 mm. 

 long, slender, resembling those of C. perspinosa but with the distal ends of the segments 

 not so strongly spinous. 



The radials project slightly beyond the edge of the centrodorsal. The IBrj are 

 oblong, slightly over twice as broad as long, with the ventrolateral edges shghtly 

 produced into a thin border by which adjacent IBr, are in apposition. The IBrj 

 (axUlaries) are broadly pentagonal, twice as broad as long, with the lateral borders 

 somewhat more than half the length of those of the IBri with which they make a 

 straight line, and with the same ventrolateral projections; a slight constriction is 

 usually present just below the lateral angles. 



The 10 arms are 80 mm. long, resembling in general those of C. svxivis. 



Pa is absent. Pj is 6 5 mm. long, small, tapering rapidly to a slender and delicate 

 tip, with 15 or 16 segments. The first segment is twice as broad as long, the second is 

 somewhat longer, the third is about as long as broad, the fourth is similar, and those 

 following very gradually increase in length to about half again as long as broad, 

 becoming again about as long as broad in the terminal four or five. P2 is 15 mm. long, 

 moderately stout and very stiff and spinelike, with about 20 segments of which the 

 first is about twice as broad as long, the second is slightly longer, the third is nearly 

 half again as long as broad, and the remainder are about twice as long as broad; 

 beginning on the second segment there is a faintly indicated broadly rounded keel 

 rtirming along the middle of the outer side, as on Pi; on the third and following seg- 

 ments the distal dorsal edge projects in the line of this keel in a narrow fringe of spines 

 which broadens on succeeding segments, the spines at the same time becoming longer, 

 and being supplemented by additional spines on the ventrolateral angles of the 

 segments. P3 is similar to P2, usually about 1 mm. shorter. P4 is 10 ram. long, 

 resembling P2 and P3, though not quite so stiff, with 15 segments. P5 and the following 

 pinnules very slowly decrease in length and stiffness, at the same time becoming more 

 slender with the spines on the distal ends of the segments less and less pronounced. 

 P, is 8 mm. long and Pn is 7 mm. long, each with 15 segments. From this point the 

 pinnules very gradually increase to 10 mm. distally, the distal pimiulcs being slender 

 and comparatively little stiffened with 20-22 segments, which have moderately 

 everted distal ends armed with fine spines. The distal pinnules are somewhat com- 

 pressed laterally. 



Notes. — The preceding description is based upon the four specimens from Inves- 

 tigator station 61, the type locality. 



The specimen from Albatross station 5355 has the arms 60 mm. long. 



One of the two specimens from Albatross station 5356 has the arms 95 mm. long 

 and the cirri XIV, 30-40, 25 mm. long; the other is smaller. 



These three specimens from Albatross stations 5355 and 5356 were compared 

 directly with the type specimen, now in the Indian Museum, Calcutta, and no differ- 

 ences were foimd. 



