54 TPIE VOYAGE OF H.M.S. CHALLENGER. 



Front fe mo ixi less stout thau in the male. 



Genital segments : first below longer than all the ventral abdominal segments together, 

 hind margin coneave, posterior angles obliquely rounded. Second below with the edges 

 of the valves overlapping each other a little. 



The larva is similar to the adult (with the usual differences), but with the leases of 

 the front femora and antennpe, as well as the under side of the body more widely pale, 

 and the leathery parts of the integuments above reddish-brown. The species occurs in 

 large " schools " on the surface of the sea near Aden, and the larvae, which seem to dislike 

 the wind mon' than the adults, take shelter in the lee of piers. 



9. Halohates proavvs, n. sp. (PL II. fig. 1). 



Oblong, rather wider behind the middle. Slaty grey aliove and lielow. Head with 

 an oblique transverse reddish-yellow spot on each side, nearly forming a band on the hind 

 margin. Antennae and legs fuscous brown. Gula, front acetabula at the margins, and 

 front 00X86 at the apex ; most of middle coxpe ; sternum ]30steriorly, at least sometimes ; 

 a larofe triangular brown-edoed blotch on the under outer side of the middle acetabula, 

 and the adjacent hind margin of mesosternum, as well as the greater part of the abdomen 

 below, yellow ochreous. Abdomen with first and second ventral segments in part, the 

 sixth at the sides, a spot at the base on each side of the first genital below, and the 

 tips of the horns of the second genital, more or less fuscous brown. Trochanters at the 

 apex, front femora with a long streak on the under side, middle femora with a spot at 

 the base below, as well as sometimes the disk posteriorly of the mesosternum, brownish 

 ochreous. Antennae: third joint about two-thirds the length of the second, fourth joint 

 subequal in length to second. Front tarsus : first joint nearly two-thirds the length of 

 the second. 



$ . Length 4, breadth 1"5, middle femur 4 '25 mm. 



Hahitat. — Gilolo (British Museum and Brussels Museum). 



$ . (Jl)long, rather wider behind the middle. Slaty grey al)ove and below. Head 

 with an oblique transverse reddish-yellow spot on each side at the hind margin, nearly 

 forming a band there. Antennse and legs fuscous brown. Eyes reddish-brown. Eos- 

 trum shining lilack. Gula, sternum posteriori}', at least sometimes, margins of front 

 acetabula and apex of front coxa3, a large triangular brown-edged spot on the under and 

 outer side of the middle acetabula, and the hind margin of mesosternum adjacent thereto, 

 most of the middle- coxce, and most of the abdomen below, as well as genital segments 

 below, yellowish ochreous. Abdomen with the first and second ventral segments in part, 

 the sides of the sixth, a spot at the base of the first genital segment below, and the tips 



