i8i>s.] 79 



but the basal segment in first and third pairs exceedingly small ; terminal segment 

 deeply cleft in all three pairs ; on the front and hind feet two claws and a stiff 

 bristle are inserted in the tarsal cleft, and a delicate leaf-like process beneath the 

 foot ; within the exceedingly deep cleft of the middle foot are inserted two claws 

 and a branched series of long ciliated hairs. 



Type : T marinics, sp. n., from Jamaica. 



Trochopus marinus, sp. nov. 

 Length, 3 mm. Black, covered with dense greyish pubescence. Basal parts of 

 first antennal segments and of the front femora, the pronotiim, a dorsal longitudinal 

 central line on the raesonotum, the under surface of the thorax, and the trochanters 

 of all the legs, yellow. Tibia of leg of second pair as long as the two tarsal seg- 

 ments together, proximal tarsal segment half as long again as distal, which bears in 

 its cleft a set of ciliated hairs, with sixteen to twenty branches. 



Locality : Kingston Harbour, Jamaica. 



The head of this insect is rounded in front, the antennae being inserted beneath 

 and in front of the eyes. The first segment of the antenna is curved and slightly 

 club-shaped, bearing three or four spines towards the tip ; the second segment is 

 thickened distally ; the third is cylindrical ; and the fourth is fusiform ; there are 

 no "jointlets" as in Halobates. Ocelli are wanting. The rostrum is of the form 

 usual in the group, with four segments, of which the first two are short and the 

 third the longest ; the tip reaches beyond the insertion of the front legs (figs. 1, 2, 7). 



The thorax shows the normal threefold segmentation above. The pronotum is 

 narrow and transverse ; the raesonotum large and hexagonal, with sinuate hind 

 margin ; the metanotum narrow and transverse. Beneath, the pi'othoi'ax and meso- 

 thorax are fused together, while the metasternum is transverse and similar to the 

 abdominal sterna. The front pair of legs are inserted close together near the centre 

 of the body. The mesothorax and metathorax are expanded laterally to receive the 

 large globular coxee of the second and hind pairs of legs. 



The abdomen is composed of nine visible segments above and below, the first 

 stemite being largely hidden by the metasternum. In the female the broad reflexed 

 margins reach back to the hinder edge of the seventh segment (fig. 1). The eighth 

 segment is divided beneath by a longitudinal cleft (fig. 7), the ninth is hemispherical. 

 In the male the reflexed margins are continuous with the pleurae of the ninth seg- 

 ment (fig. 8). The eighth segment beneath has a concave hinder edge with a small 

 central prominence (figs. 9, 10), from which project a pair of claspers with bluntly 

 curved tips armed with numerous short spines, joined together above by a chitinous 

 bar (fig. 8), and surrounded by a fine delicate membrane Whether these claspers 

 are normally in the protruded condition shown in the single specimen which I 

 have figured (figs. 8, 9, 10) must remain doubtful for the present. I can detect no 

 other sexual distinction in the specimens before me. 



The front legs are of moderate length, the femora evenly cylindrical and fur- 

 nished with a series of long, fine hairs (fig. 1). The tibiae are thickened distally and 

 clothed with numerous liairs, some of which, overhanging the foot, are club-shaped 

 (fig. 3). The tarsus has two segments, of which the proximal is very small and hai-d 



