A MONOGRAPH OF THE EXISTING CHINOIDS 411 



Antedon (part) HARTLAUB, Nachr. Ges. Gottingen, May, 1890, p. 187; BELL, Proc. Zool. Soc. 



London, 1894, p. 400; BELL, in Gardiner, Fauna and Geography of the Maldive and Lacca- 



dive Archipelagoes, vol. 1, pt. 3, 1902, p. 224. 

 Comanlhina (part) A. H. CLARK, American Journ. Sci., ser. 4, vol. 32 (old ser., vol. 182), 1911, 



p. 130. 

 Comanlheria (part) A. H. CLARK, Memoirs Australian Mus., vol. 4, pt. 15, 1911, pp. 716, 723. 



Diagnosis. A genus of Comastcrinao in which the elements of the IBr series 

 and the first 2 ossicles following each axillary are united by syzygy; the IIBr series 

 are 4 (1+2, 3 + 4), more rarely partly 4 (1 +2, 3 + 4) and partly 2 (1+2); the IIlBr 

 and later division series are 2 (1+2) or, very exceptionally, of 4 elements; terminal 

 combs are not confined to the proximal pinnules, but are found at more or less fre- 

 quent intervals on the middle and distal pinnules. 



Geographical range. From China, southern Japan, the Philippine, Gilbert, 

 and Society Islands, Fiji, and Australia, south to Port Molle, Queensland, and Port 

 Walcott, Western Australia, westward to the Maldive Islands. 



Bathymetrical range. From the shore line down to 290 (?538) meters. Of the 

 12 species, 11 occur in 0-100 meters, 5 in 100-150 meters, 3 in 150-200 meters, and 

 2 are found in depths greater than 200 meters. 



Remarks. The species of this genus all have a great development of small 

 spines on the brachials and especially on the pinnule segments, so that they have a 

 characteristic "feel." But a similar "feel" is possessed by Comanthus samoana and 

 by some forms of Comanthus parvicirra. 



They also have a very characteristic appearance. The arms are very slender 

 and the elements of the division series and the lower brachials usually have the 

 sides distinctly concave. The edges of the elements of the division series, including 

 those bordering the syzygial lines, are, excepting in the very largest specimens, 

 rather prominently spinous. 



Excepting in C. multifida, the color is almost invariably more or less bright 

 yellow, with a narrow median dark stripe on the division series and arm bases. 

 But this type of coloration is not entirely constant, for C. bremcirra ( = parvus) is 

 sometimes black with yellow pinnule tips. C. multifida, is variously colored (see 

 vol. 1, pt. 2, p. 706), but apparently this species is never yellow, or at least wholly, 

 when fully grown. 



In the very large species of Comaster the IIBr and following axillaries typically 

 bear a division series on one face and an undivided arm on the other, and the divi- 

 sion series and undivided arms alternate in position on succeeding axillaries. This 

 gives the appearance of 2 stout arm trunks on each ray, of which the IIBr series are 

 the bases from which, on every other ossicle, an undivided arm arises, the successive 

 arms alternating in position, the first being external, the second internal or adradial, 

 the third external again, and so on. More rarely the IIIBr series serve as the bases 

 of these arm trunks, in which case there are 4 to each ray. Division series which 

 occur out of the regular order, as on the side branches from these main trunks where 

 one would expect an undivided arm, are usually of 4 elements instead of the usual 2. 



This very characteristic arrangement of the division series whereby 2 main 

 arm trunks arise from each IBr (more rarely from each IIBr) axillary recall the 

 conditions in the large species of Comatella. But in Comatella the undivided arms 



