40 CAPRELLTDJ3. 



in appearance, and have the posterior margin of the 

 penultimate joint armed with four radiating spines. The 

 fourth pair are like the third, hut smaller, while the fifth 

 are so much smaller and imperfect in their condition 

 as to partake of a rudimentary character. They are, 

 moreover, directed backward ; that is, contrary to the two 

 posterior pairs, and therefore contrary to its normal con- 

 dition. The two posterior pairs of legs are attached 

 near together, in consequence of both being situated at 

 the posterior extremity of their respective segments, 

 the last of which is much shorter than any of the others. 



This single feature is sufficient to enable the observer 

 to detect an animal of this genus, however otherwise 

 damaged, since in Caprella, &c., the last two joints are 

 always short, and hence the last three pairs of legs are 

 always in close juxtaposition. The last two pairs of legs 

 are longer than the others, and have the penultimate 

 joint, for nearly two-thirds of its length, armed with two 

 spines, opposed to the extremity of the finger which 

 closes upon the preceding joint. The tail is rudimentary, 

 consisting, when recent, of a cylindrical tube, without 

 any limbs except two pairs of rudimentary, styliform 

 appendages, situated near the extremity of the preceding 

 segment, which probably fulfil the same office as their 

 homologues in the male brachyurous Crustacea. 



We anticipate that the geographical distribution of 

 this species will be ultimately found to be more general 

 than our experience has yet ascertained. It was first 

 taken as British by Montagu on the southern coast of 



and Montagu belong) ; and the second with the first pair of hands triangu- 

 lar, somewhat lobed at the base, the wrist deeply serrated, the second pair 

 of hands oval with two teeth at the base, and serrulate along the palm, head 

 very obtuse in front, and the branchial lamellae smaller and cylindrical (to 

 which all the Berwick specimens are referable). 



