A MONOGRAPH OF THE EXISTING CRINOIDS 



405 



is between brachials 3 + 4, with rarely a partially developed syzygy between brachials 

 1 + 2 ; the first brachial pinnule is always on the second brachial ; and the genital 

 pinnules are not especially stout, their component segments not noticeably short. 



Geographical range. From southern Japan eastward to Tokyo Bay, the Bonin, 

 Pelew, Caroline, Gilbert, and Society Islands, Samoa, Tonga, Fiji, New Caledonia, 

 New Zealand, Tasmania, and the southern coast of Australia westward to Baluchistan, 

 the Seychelles, Madagascar, Natal, and the Cape of Good Hope as far as Simons and 

 False Bays. 



Bathymetrical range. From the low-tide mark down to 548 meters. The relative 

 frequency of the included genera at different depths is as follows: 



0-100 meters 4 



100-200 meters 4 



200-300 meters. . . 3 



300-400 meters. 

 400-550 meters. 



Remarks. The subfamily Comasterinae is a very homogeneous group. All of 

 the included species have more than 10 arms, and in some the number may be, in 

 certain individuals, in excess of 150. Within fairly narrow limits the number of arms 

 is constant in each species. While a very few of the species (as for instance Comaster 

 minima} are small and delicate, several, including at least one in each genus, are of 

 great size and massive structure. 



The division series are always 4 (3 + 4) or 2, either (beyond the IBr series) 

 exclusively 4 (3+4), or 4 (3 + 4) and 2 mixed in various proportions. The division 

 series of 2 elements may occur in fixed and definite positions (as in Comaster, Coman- 

 theria, and Comanthina) , or they may be irregularly scattered (as in Comanthus). 



In one genus (Comaster) the synarthries in the division series and arm bases are 

 usually replaced by syzygies. The first pinnule on the arms is always on the second 

 brachial, and there is always a syzygy between brachials 3 + 4. All of the pinnules 

 are always present, as in the Comactiniinae. 



All of the included genera contain species in which the cirri are wholly absent, 

 either invariably, frequently, or occasionally. These species are confined to the 

 area bounded by the Philippine and Caroline Islands, tropical Australia, and the 

 Maldive Islands. In one genus (Comanthina) all the included species are typically 

 without cirri when adult, but all the other genera include species with numerous and 

 well-developed cirri which may be small and weak (as in Comanthus parvicirra) but 

 are usually large, and may be very large and stout (as in Comanthus bennetti and 

 in C. pinguis). 



The cirri have the distal segments shorter than the proximal, usually much 

 shorter, and they are invariably, on all or at least some of the cirri, provided with 

 dorsal processes. 



Species without cirri, or with deficient cirri, are confined to the area bounded by 

 the Philippine and Caroline Islands, tropical Australia, and westward to the Maldive 

 Islands. 



Gisle"n wrote (1922) that within the subfamily Comasterinae 3 different types 

 of terminal combs can be distinguished. The first, which he called the Comaster 

 type, is short and strongly rolled and composed of a few large teeth placed closely 

 together. The combs occur on every second or third pinnule to rather far out on the 



