96 GAMMARIDiE. 



running across the axis of the joint, and covered below 

 and at the apex with a fur of short hairs, amongst which 

 the small finger is lost to observation, except under very 

 high magnifying power. It must therefore appear, if 

 there be any prehensile capability in this and other 

 similar appendages, that it is not obtained through any 

 assistance that can be derived from the finger, but by 

 the pressure of the hand back against the hairy cushion 

 on the inferior surface of the wrist. The first two pairs 

 of walking legs are small, and the last three appear to 

 be more robust ; they are rather curved, and have the 

 second joint developed to a broad oval shape, which is 

 produced infero-posteriorly, so far as to cover the next 

 joint; their posterior margins are crenulated, and have 

 a short hair springing from the depression between each 

 lobule ; the fourth joint is broader in the fifth pair of 

 legs than in the two following pairs ; the sixth joint is 

 sJightly curved, the two margins being parallel. The 

 three pairs of caudal appendages are short ; the branches 

 (which are of equal length on each) are very short, those 

 on the posterior being a little the longest. The terminal 

 scale is cleft through more than half its length. The 

 tail generally has the appearance of being a powerfully 

 thrusting organ, and it is undoubtedly used to propel the 

 animal either backwards or forwards. 



The colour of the animal varies from a transparent 

 pale yellow, in the young state, to that of a deep yellow 

 or light brown tint. The eyes are red in the young, but 

 become black in the adult animal. The structure of the 

 skin appears not to exhibit any decided markings when 

 examined by the microscope, but the surface generally is 

 covered with minute solitary spinules or short hairs, dis- 

 tantly scattered. 



This description, as well as our figure, is taken from a 



