i 4 6 



distinct keel in the middorsal line and usually ;i smal! spine in 

 the centre of the distal dorsal border; 10 — i: arms; IIBr series, 

 if present, 2 (Queensland and Timor to the Philip- 



pine Islands; southern Japan) Daidalometra 



e' arms not narrow nor strongly compressed laterally, and with 



110 carination; sides and proximal and distal edges of the 



ossicles of the division series nearly or < j nïte smooih 



f' division si-ri>-s and arms broad, wel] rounded dorsally; habitus 



rol. ust (Kermadec Islands to the Moluccas and 



the Philip pin es) Aglaometra 



t division series and arm bases narrower, subcarinate ; general 

 habitus slehder (Laccadive Islands to the Lesser 

 Sun da Islands, Fiji, the Kermadec Islands and 



New South Wales) Stiremetra 



d cirri short and stout, with less than 30 segments; division series 

 and arm bases narrow, well rounded dorsally, appearing narrow 

 and only slightly rlattened against their neighbours; 10—20 arms; 

 division series all 2 (Kei Islands to southern Japan and 



the Hawaiian Islands) Parametra 



a More than 10 arms 



b 1 dorsal surface of tin- ossicles of the division series and of the arm bases 

 with numerous prominent spines which may be more or less confined 

 to the borders of the ossicles and to the median line, or generally 



itributed over the dorsal surface 

 c' more than 15 arms; division series strongly rounded dorsally, appearing 

 relatively narrow 



d 1 IIBr series all, or mostly, 4 (3 -j- 4); 15 — 28 arms; a more or 

 less prominent median keel on one or both of the elements of 

 each division series and oi the first brachial pair; 110 overlapping 

 spines on the brachials the distal borders of which are evenly 

 rounded and very spinous (Moluccas to the Philippine 



and II awaiian Islands) Oceanometra 



d 2 all the division series 2; 30 arms, a single IIIBr series being 

 developed on the inner side of each IIBr series; 110 tracé of a 

 median keel on the elements of the division series or of the tirst 

 brachial pair; each brachial beyond the fifth or sixth bears a Ion-. 

 broad, thin, sharp pointed curved spine of which the hase entirely 

 spans the ossicle longitudinally and the tip, directed nearly parallel 

 t<> the axis of the arm. extends tor some distance over th< suc- 

 ng brachial: on succeeding brachials these s|)ines alternate 

 either side of the median line; toward the end of the arm they 



