CUMACEA FEOM THE COPENHAGEN MUSEUM. 3a 



Gynodiastylis l^vis, sp. n. (Plate XXXV. figs. 32-39.) 



Description of adult Female. — Total length 4"1 mm. 



Carapace a little more than one-fourth of total length, its vertical height less than 

 half of its length, subcylindrical, narrowed in front; dorsal outline slightly arched as 

 seen from the side. Pseudorostrum straight, slightly deflexed, truncate, not more 

 than one-eiglith of total length of carapace. Antennal notch slightly marked, defined 

 by a VL-ry small antero-lateral tooth. The snrface of the carapace is quite smooth. 

 The ocular lobe is slightly prominent as seen from the side ; it is devoid of pigment 

 and presents no distinct facets. 



The first free thoracic somite is very short. The second is very long, more than a 

 third of the length of the carapace as measured along the dorsal edge, and its pleural 

 plate is produced anteriorly as a narrow lobe. The tliird and fourth somites are 

 together little longer than the second in the dorsal line; their pleural plates are pro- 

 duced backwards and the articulation of the posterior legs is as in G. carinata. 



The abdomen is slightly shorter than the cephalothoracic region. The somites are 

 somewhat depressed and have faint lateral keels. 'Jhe last somite is little shorter 

 than the penultimate, about one-third longer tlian broad, and m(;re than twice as 

 broad as deep. 



The telson is little more than half as long as the last somite, its breadth less than 



two-thirds of its length. 



The antennules are shorter and more robust than in G. carinata. The first segment 

 of the peduncle is less than twice as long as broad and about equal to the other two 

 together, and the second is two-thirds as long as the third ; the flagella are short and 

 each composed of three segments. The antenna; resemble those of G. carinata. 



The mouth-parts resemble those of G. carinata, but the distal setae of the first and 

 second maxillipeds are shorter than in that species. The third maxilliped is without 

 an exopod; its basis is longer than in G. carinata and less expanded distally, where it 

 carries only two or three setae. 



The first legs have the basis nearly twice as long as the distal segments together, 

 produced distally at the inner corner as a strong tooth ; the carpus is about as long as 

 the two preceding segments together; the propodus is half as long as the carpus and 

 bears three long setae on the distal part of its inner edge; the dactylus is two-thirds 

 as long as the propodus. 



The second legs have the basis three times as hmg as broad and nearly twice as long 

 as the remaining segments together; the dactylus and propodus arc subequal and 

 together shorter than the carpus. 



The remaining legs are stout. The merus in the fifth pair is more than twice as 

 long as the carpus; the dactylus is shorter than the propjdus and its terminal spine 

 is short and claw-like. 



The uropods have the peduncle two-thirtls as long as the last somite and reaching 



