CUMACEA FEOM THE COPENHAG-ElSr MUSEUM. 29 



Vauntompsonia cristata Spence Bate. 



Vauntompsonia cristata G. 0. Sars, Arch. Math. JNTaturvid. iv. p. 13, pis. xxiii.-xxvi. (1879) ; 

 Caiman, Fisheries, Ireland, Sci. Invest. 1904, i. (1905), p. 17, pi. i. fig. 1. 



To this species I refer, not without some hesitation, a number of male specimens 

 from the West Indies. They differ from British and Mediterranean specimens in their 

 much smaller size (not exceeding 3, as against 5 mm.), but no differences of structure 

 can be detected by a careful examination except that the peduncle of the uropods is 

 relatively shorter and thicker, being shorter than the exopod and less than four times 

 as long as thick. 



Occurrence. — " Cruz Bay, St. Jan" (Danish West Indies), " Chr. Levinsen, 6/1/96." 

 About twenty specimens, all males. Copenhagen Museum. 



Vauntompsonia arabica, sp. n. (Plate VII. figs. 20-24.) 



Description of adult Male. — Total length 3'1 mm. 



The carapace is distinctly more than one-fourth of the total length, its vertical 

 height about two-thirds of its length. Seen from the side the dorsal edge is distinctly 

 arched. Pseudorostrum very short and truncated. Anterior edge without teeth. 

 Antero-lateral angle obtuse, with a single inconspicuous denticle. 



The anterior lobe of the fifth leg-bearing somite is broader, and the notch defining 

 it above is less distinct than in V. cristata. 



The abdomen is about equal in length to the cephalothoracic region and is stouter 

 than in V. cristata. 



The antennules have the peduncle shorter and stouter than in V. cristata, the second 

 segment is without the stout setae present in the male of that species, and the third 

 segment is longer than the second. 



The third maxilliped has the basis without serrations on its inner edge. 



The first legs are considerably shorter than in V. cristata, extending beyond the 

 pseudorostrum by little more than the length of the terminal segment. The basis is 

 two-thirds of the length of the distal segments together. The dactylus is two-thirds 

 as long as the carpus and little more than half the length of the propodus. 



The second legs have the basis about equal to the distal segments ; the last segment 

 is less than four times as long as broad and not longer than the two preceding 

 segments. The posterior legs, and especially their basal segments, are relatively shorter 

 than in V. cristata. 



The uropods have the peduncle equal in length to the terminal somite and rather 

 less than four times as long as thick, with eight subequal spinules and a longer distal 

 one on its inner edge. The exopod is equal to the peduncle, with three minute spines 

 on its outer edge, one long and two short spines terminally and one small spine on the 

 inner edge. The endopod extends beyond the exopod by half the length of its distal 



