190 



s. GOTO 



Superomarginals. — The number of saperomarginals where 

 counted is shown in the foregoing table. 



Each superomarginal is armed with a small conical spine 

 situated on its outer border, and directed obliquely outwards and 

 distally (PL IV, fig. 62, 67). The spines on the first two plates 

 at the interbrachial angle are usually situated a little more in- 

 ternally than the rest, and are sometimes foand even close to the 

 inner border ; they may also be perceptibly larger than the others. 

 The spines are usually absent from a few plates at the extreme 

 end of the arms, and in one or two specimens that have come 

 under my observation the superomarginals were entirely unarmed. 

 In such cases we have to depend entirely on the combination of 

 other characters for identification. An interradial plate may or 

 may not be present. The first superomarginals, as also the 

 second and third, may also be destitute of spines in some speci- 

 mens, showing the unsafeness of depending for determination on 

 a single character, however striking it may usually be. In a 

 small specimen from Enoura, No. 1 of the foregoing table, the 

 unarmed condition went so far as to extend to the first 3-11 

 superomarginals on either side of the interradial line. 



The general covering of the superomarginals is granular (PI. 

 IV, fig. 67). The granules are short cylindrical and rather well- 

 spaced on the abactinal surface, but on the outer side they are 



