56 



terior pair of the last mentioned feet. The Post- Abdomen is divi- 

 ded into three articulations, and a terminal cordiform appendage 

 constituting a tail proper. The anterior segment has no lateral 

 elongation, in place thereof its extremities are produced inferiorly, 

 giving insertion to the posterior pair of true feet ; these feet differ 

 only from the preceding ones, in being rather smaller and having 

 the terminal nail more curved. The two last segments are some- 



what similar to those of the j 



ugh infe 



The three segments have on their under sides each a pair of pedi- 

 form appendages, composed of a single compressed joint, to which 



vesicular bursae, fringed with branchial fibres : the inferior ones of 

 the middle pair have inserted along their inner edge a flexile seta- 

 ceous style, extending backwards about twice th» length of the 

 whole appendage. Tail cordiform : a raised and reflected rim ter- 

 minating in an acute spine near the outward margin, gives the an- 

 terior part the appearance of a distinct segment ; longitudinally 

 through the centre is an elevated, sharp, muricate ridge, terminat- 



situated a pair of short and reflected teeth : the posterior margin 

 is slightly elevated, having its edge armed with a row of sharp 



er thick, serrate and acuminate leaflets, inserted into a moverbirpe- 

 duncle ; their motion is lateral, and when at rest the superior 

 shuts over the inferior one like the sticks of a fan. At the origin 



are inserted in pairs eight membranous lamina, meeting eacrotli- 

 er by a longitudmal line in the centre, when they form the perfect 



which is rather thicker, and is diagonally articula^ed^''*^'^"^' 



Females carry their ovaTetweets;ales under the thorax Ova 



orbicular, nearly a line in diameter of e, 

 Co^.. of the ammal, an olivaceous green.' " ""^^ 

 Length Uvo and three quarter mches. Breadth two and one quarter 

 Hab. Seas, along the coast of Pataeonia H ^ 



South Sheilands. ^'''gonia. Cape Horn, New 



