A MONOGRAPH OF THE EXISTING CRINOIDS 007 



the arm less oblique, though remaining of about the same proportionate length. 

 From about the second onward the brachials have slightly overlapping distal cuds. 



Syzygies occur between brachials 3 + 4, again from between brachials 11+12 to 

 between brachials 14+15, and distally at intervals of usually 4 muscular articulations. 



P D is from 12.5 to 25 mm. (usually between 17 and 23 mm.) in length, mod- 

 erately stout basally but tapering rapidly in the proximal third or half and very 

 slender distally, composed of 35-40 segments which have prominent and overlapping 

 distal ends. The terminal comb is made up of 7-8 moderate-sized spatulate teeth 

 which may be provided with spinous borders; some or all of the teeth may bo re- 

 peated on the inner side of the pinnule. P P is similar to P D and only slightly, if 

 at all, shorter and more slender. P t is similar to P P , somewhat shorter and slightly 

 more slender. In a specimen with P D from 23 to 25 mm. long, P P is 20 mm. long 

 and PI is 17 mm. long. P 2 is small and weak, from 7 to 10 mm. long. P 3 and the 

 following pinnules are of the same length but considerably stouter. The distal 

 pinnules are slender and delicate, 13 or 14 mm. long. The terminal comb disappears 

 after PI or P a . The segments of the lower and middle pinnules have prominent 

 distal ends, and the distal vcntrolateral angle is strongly produced; both of these 

 features gradually die away distally, disappearing first from the distal part of the 

 pinnules, then gradually more and more toward the base, and finally altogether. 



The color in alcohol is brownish white to dark brown, deep blackish brown, or 

 dark grayish green. Dried specimens are green, olive, or various shades of brown. 



Notes. Chadwick did not distinguish timorensis from parvicirra. He said the 

 number of arms of the specimens of parvicirra collected during the Ceylon pearl- 

 oyster fisheries investigations varied from 10 in a specimen from station XLI and 

 11 in one from station LVII to 48 in one from station IX. The 10-armed example 

 is a specimen of Comissia chadwicki, and the specimens with numerous arms un- 

 doubtedly represent this species. He remarked that the specimens with 44 and 48 

 arms have no spines, or but feebly developed ones, on the penultimate segment of 

 the cirri, and in them the IBr series and the IIB^ are in close lateral contact. 

 Several IIBr 2 series occur in most of the specimens. 



Of the 3 specimens from Galle, Ceylon, 1 has 35 arms 100 mm. long, the IIIBr 

 series being all present on 3 of the rays; 2 are present, developed externally, on the 

 fourth, and 1 is present, developed internally, on the fifth. Another also has 35 

 arms. The third has 31 arms 75 mm. long. 



The specimen recorded as Antedon, sp. by Bell had 39 arms and only a few cirri 

 with about 13 segments and the opposing spine obsolete. He noted that the IIBr 

 and IIIBr axillaries are united to the preceding ossicles by syzygy, and the first 

 brachial syzygy is between brachials 3 + 4, while the second is between brachials 

 12+13. These characters are sufficient to identify the specimen as Comanthus 

 annulata. 



Two of the specimens recorded (as parvicirra} from Ceylon by Bell in 1887 are 

 in the British Museum. One of these has 43 arms. Seven of the IIBr series are 

 2 and 3 are 4 (3+4). The IIIBr and subsequent series are all 4 (3+4). There are 

 only very small rudiments of citri. The other specimen has about 40 arms. 



Dr. Hubert Lyman Clark wrote that the 22 specimens from Ceylon that he 

 examined had from 40 to 54 arms. The division series were nearly always 4 (3 +4). 



