i9i 



In young- individuals in which the radials are still about half as large as the IBi-j (see 

 the "Challenger" Report, pi. 16, fig. 5) there is but little tracé of the dorsolateral processes 

 characteristic of the adults; they are only slightly evident, though they can be made out as a 

 thickened ridge in the place they will eventually occupy; at this stage also the genital pinnules 

 are slender and evenly tapering, showing 110 tracé of the lateral expansion of the segments 

 which is so marked a feature in the fully grown. 



As the radials become shorter the proximal border of the IBrj becomes produced so 

 that it conceals the radials and proximal edge of the centrodorsal when the animal is viewed 

 laterally. The dorsal surface of the radials is gradually resorbed as the proximal margin of the 

 IBr, is produced, so that the rays and arms appear to be too large for the radials and 

 centrodorsal, giving the appearance of having been glued upon them instead of having grown 

 out from them. 



In very large specimens the produced borders (proximal and lateral) of the IBi'j, which 

 are typically smooth, become crenulate and scalloped. 



The two examples from Stat. 124 resemble those from Stat. 122. 



Charitometra A. H. Clark. 



9 



Key to the Species of the Genus Charitometra. 



a 1 Brachials from the fourth onward with thickened, everted and tubercular distal 

 borders, this character gradually dying away after the brachials become triangular ; 

 arms about 100 mm. long (Kermadec Islands; ?Fiji; 11 34 and r 2430 

 M e t r e s) basicurva 



a- Brachials with unmodified distal borders, the arms appearing quite smooth; arms 



about 90 mm. long (Kermadec Islands to Fiji; 11 34 Metres) . . . . iucisa 



Strotometra A. H. Clark. 

 Key to the Species of the Genus Strotometra. 



a 1 Distal border of the second brachial everted, standing out at right angles to 

 the dorsoventral axis of the arm as an enormous this rounded or fan-shaped 

 crest, with a rounded or broadly scalloped edge, sometimes divided in the 

 middle, which may reach 1.5 mm. in height, the height being three or four 

 times the greater (outer) length of the ossicle; the fourth brachial (the epizygial 

 of the first syzygial pair) has a similar crest nearly, if not quite, as large, the 

 fith brachial has a crest about half as high, and more irregular; the sixth has 

 a strongly produced and thickened distal edge, which is coarsely scalloped ; 

 the following brachials are of the normal type, with slightly produced and 

 finely spinous distal border-s (e ast of the northeastern end of Celebes; 

 1165 — 1264 Metres) # . . . ornatissimns 



a" None of the brachials have extravagantly everted distal borders • 



