KEPOKT ON THE PELAGIC HEMlI'TKitA. 4<> 



Pronotum of tla- usual form, disk somewhat tiat, rather hullmwd in the middle 

 posteriorly, and with a transverse fovea on each side anterior!}-. Mt'sonotum widest a 

 little behind the front maroin, disk verv convex. Mrsostcriinni with a verv indistinct 

 pereurrent longitudinal mesial line. 



Front legs : femora very stout (comparatively), nearly equally thick to middle, then 

 narrowing to apex ; tiljia about four-fifths the length of tlie femur ; tarsus (PI. I. fig. 7,f.t.) 

 about three-fifths the length of the tiliia, first joint two-fifths the length of the second, 

 which is cleft about the middle. 



Middle legs : trochanters armed on inner side with short spines, as is the femur ; femur 

 rather shorter than the tibia and tarsus taken together ; tibia a little shorter than the 

 tarsus ; tarsus (PI. I. fig. 7, m.f.) first joint seven times as long as second joint. 



Hind legs : femur armed as middle femur, al)Out one-fifth longer than the tibia and 

 tarsus together ; tibia armed on all sides with scattered small sjunes ; tarsus cleft at 

 about two-thirds of the length. 



Abdomen : peculiarities of the conni'xivum have been noticed in the generic 

 description. 



Genital segments : first below as long as foui' of the abdominal ventral segments, 

 transversely convex, sides parallel. Second with the horns reaching about three-fourths 

 the length of the third below; the margins of the lun-n (PL 111. fig. 24) are not 

 thickened, and on the basal half are a few long hairs pointing inwards, and arising from 

 the disk ; apical half of the disk set with short, stout, outward-pointing teeth ; near the 

 base of the horn, and between it and the posterior angle of the segment, is a tubercle. 

 Third segment above (PI. I. fig. 7, g.), with the lateral angles moderately produced ; on 

 each side below is a patch of sharp spines pointing forwards. 



$ , Ovate, widest at al)out the middle. Hind margins of the ventral alidominal .seg- 

 ments sometimes luteous. 



Head and mesothorax more convex than in the male. 



Front tibia nearl}' as long as femur. 



Middle legs : trochanters unarmed, femora less strongl}' armed. Sometimes the 

 middle and hind legs are scarcely armed. 



Abdomen below (PI. I. fig. 7, ? ab. b.) : segments 1st to 5tli, each rather elevated 

 in transverse middle line ; sixth with a suboblicpe transverse furrow not quite reaching 

 the middle. 



Genital segments: first bclow^ as long as three of the ventral abdominal segment.s 

 together, transversely convex, sides tum.id, hind nmrgin straight in the middle, each 

 side somewhat oblique. 



Halobates serieeiis has been found in IMarch, April, June, July, and October, but pro- 



(ZOOT.. CHALL. EXP. — I'ART Xl.K. ISS.*?.) ^ ' 



