747 



THK HKCENT CRINOIDS OF AUSTRALIA— CLAKK. 703 



Differential Characters. — The various species of Comaster are 

 most readily recognised by their peculiar type of arm division. 

 The II Br series are 4 (3 + 4), but the following series are all 2, 

 usually appearing as if united by syzygy ; III Br series are internal 

 in tlieir appearance, so that, if only II Br series and III Br series 

 are present, the thirty arms will be arranged in 1, 2, 2, I order, 

 the following division series follow the internal III Br series and 

 are developed on either side alternatelj'^, no that each I Br series 

 appears to give off two stout trunks giving off undivided arms 

 on alternate segments, and finally terminating in a pair of 

 undivided arms. The presence of forty arms due to the presence 

 of all the II Br and all the III Br series is rare, but occasionally 

 is found ; species possessing such an arm arrangement are easily 

 recognised by the II Br 4 (3 + 4) and the III Br 2 series. 



The presence of terminal combs at intervals on the outer 

 pinnules also distinguishes the genus Comas/.er from all the other 

 genera of the Comasteridre. 



Range. — Maldive Islands to Northern Australia, Fiji, the 

 Philippines, and the Gilbert (Kingsniill) Islands. 



COMASTEK TYPIOA {Loven.) 

 Anledon steUatus, Liitken, MS. 

 Phanogenia typica, 1866, Loven, Of v. k. Vetensk. Akad. 



Forhandl, 1866, No 9, p. 231, Hg. on p. 230, a-h (New 



Hakbouk, near Singapore). 

 Actinometra midtifida (part), 1884, Bell, Rep. Zool. Coll. H.M.S. 



"Alert, p. \%'d {Prince of Wales Channel; Thursday Island; 



Torres Strait). 

 Actinometra variabilis, 1884, Bell, Rep. Zool. Coil. H.M.S. 



" Alert," p. 169, pi. xvii., figs. B, Ha (Thursday Island) ; 



1894, Proc. Zool. Soc. 1894, p. 394 (A". TF. Australia, 9-S8 



fms.). 

 Actinometra typica, 1888, P. H. Carpenter, "Challenger" 



Reports, Zool., vol. 26, p. 296, pi. Ivii., fig. 1. 

 Comaster typica, 1909, A. IT. Clark, Zool. Anzeiger, vol. 34, 



p. 365 {off Port Walcott) ; Vidensk. Medd. fra den naturhist. 



Forening i Kobenhavn, 1909, p. 139. 

 The systematic position of the Actinometra variabilis described 

 and figured by Professor Bell in the Report upon the "Alert" 

 Collections has puzzled me considerably. Carpenter placed it in 

 the " Parvicirra gr^up " of "Actinometra," all but one of the 

 other species of which fall into the genus Gumnnthus as no^v 

 understood ; but the branching of the arms as shown in Bell's 

 figure is of a curious type exclusively confined to the genus 

 Comaster. Tiie general appearance, too, of the specimen figured 

 by Bell is that of a si)ecies of Comaster. 



