BARBADOS-ANTIGUA REPORTS 97 



Family Sphaeromidae 



Sphaerominae hemibranchiatae 

 . ExosPHAEROMA NUTTiNGi new species 

 Figures 1-2 



Body elongate-ovate, smooth, ground color creamy yellowish, irregularly 

 mottled with fine black splotches. 



Head two-thirds as long as wide with frontal margin produced to a 

 median point on either side of which it is moderately excavated and thence 

 recurvate for the reception of the antennal joints. Eyes large, round, occu- 

 pying the entire postlateral area of the head. First antennae with the basal 

 article elongate, broad, flattened, second article half as long as the first, 

 very convex; the third article slender, cylindrical, two-thirds as long as the 

 first, and a flagellum of eight slender subequal articles and extends almost 

 to the posterior margin of the first thoracic segment. The second antennae 

 have the first and second joints short, subequal, the third and fourth joints 

 each slightly longer than the second, the fifth joint slightly longer than the 

 fourth and a flagellum of eleven tapering subequal articles which extends 

 almost to the posterior margin of the third segment. The maxillipeds have 

 the lobes of the distal four joints much produced. 



The first thoracic segment is slightly longer than any of the others which 

 are subequal, the epimera are easily distinguished and have their respec- 

 tive lateral margins rounded and sculptured. The seven pairs of legs are 

 similar, subequal, irregularly, sparsely set with spines along the inner side. 



The abdomen has the first thoracic segment a trifle longer than the sev- 

 enth thoracic segment and bears three transverse lines indicating the coales- 

 cence of four segments, the terminal segment is convex, domelike, with the 

 posterior marginal area on a slightly lower plane than the central area; the 

 posterior margin is broadly rounded, the extreme median area has a broad 

 shallow excavation on the ventral surface, the distal termination of this 

 channel causes a vague almost invisible truncation of the dorsal margin. 

 The uropoda have the peduncle rounded, knob-like, its articulation with the 

 inner branch being diificult to distinguish; the inner branch has the inner 

 lateral margin relatively straight, the outer margin broadly rounded, the 

 distal margin crenulate; the outer blade is four-fifths as long as the inner 

 blade and is broadly oval with its posterior margin crenulate. 



Pleopoda one and two are subequal, similar, fringed; pleopoda three has 

 the exopod two-jointed; pleopoda four and five have the endopods thick, of 

 fleshy aspect, with deep, essentially transverse folds, the exopods submem- 

 braneous and rather pellucid, two jointed. 



The present species may be distinguished from Exosphaeroma crenulatum 

 Kichardson* by the fact that it has three transverse lines on the first ab- 

 dominal segment indicating the coalescence of four segments; these lines 



"Exosphaeroma crenulatum Richardson, Bull. 54, U. S. Nat. Mus., 1905, p. 298, 

 1. 317-318. 



