ARTHKOPOD FAUNA OF THE WEST INDIES. 395 



others, the third segment with 8 keels and a trace of the median 

 lateral ; the superior lateral keel of the first four segments strong 

 in front and terminating in a rounded lobe ; the upper edges of 

 the fifth segment squared not elevated ; the inferior keels finely 

 denticulated, a smooth crescentic area at the hinder end of its 

 lower surface ; vesicle studded beneath with setiferous pores, 

 the conical spine beneath the aculeus thickly hairy ; aculeus 

 about half the length of the vesicle, gently curved. 



Falpi punctulate above ; the humerus granular at the base, 

 with irregularly granular superior keels, finely granular in front 

 also ; hracMum studded posteriorly with setiferous pores, the 

 supero-anterior keel at most crenulate, the anterior surface 

 smooth except for a vertical series of three fine denticles above 

 at the base. Ilanus large, more than twice the width of the 

 brachium, widely and evenly rounded internally, convex above 

 and obsoletely tricostate, the lower surface also obsoletely tri- 

 costate ; the " band-back " furnished with a single keel which runs 

 obliquely backwards and upwards from above the lower articular 

 facet of the movable digit ; digits slender, not lobate, the movable 

 a little longer than the width of the hand. 



Legs smooth, the lower surface of the feet furnished with two 

 rows of spines. 



Pectines short, with 8-9 teeth. 



S • Much less smooth than the female, the carapace so 



closely punctured as to be finely rugulose ; the upper surface of 



the hand adorned with a reticulated pattern of minute granules, 



the external and internal keel of its upper surface very strong. 



Tail longer, about 4g times the length of the carapace, which is 



equal to the first caudal segment and -| of the second. The 



pectines much larger, both the shaft and the teeth being longer. 

 Measurements in millims. — $ . Total length 44, length of 



carapace 6, of tail 24, of its first two segments 6, of the fifth 5*2 ; 



length of brachium 48, width 2 ; width of hand 5 ; length of 



hand-back 4, of movable digit 6. 



S . Total leugth 46, length of carapace 6, of tail 27, of its 



first two segments 7, of the fifth 6, of brachium 5, of hand-back 



4, of movable digit 6, width of hand 5*2. 



Locality. St. Lucia {G. A. Ramage) \ St. Vincent {K. H. 



Smitli). 



Of the described species of Diplocentrus this new form seems 



to differ from D. GuncUachii in that the 1st segment of the tail 



is the only one that contains 10 complete keels. 



LINN. JOUKN. — ZOOLOGY, VOL. XXIV. 31 



