Carpenter — Rhynchota from Murray Island and Mahuiag. 145 



with a rounded point, and light yellow lateral margins and 

 prominences. All the abdominal segments are of a light-yellow 

 hue beneath. The sixth has its anterior and posterior margins 

 straight centrally, and oblique laterally, embracing the seventh 

 (first genital). This latter occupies about a third of the length of the 

 whole abdomen as seen from beneath. The eighth (second genital) 

 has its horns symmetrical and divergent, and tipped with black. 



Female (PI. xiii., figs. 3, 4). Length, 6 mm. ; breadth, 3 mm. 

 Length of front femur, 2 mm. ; of middle femur, 5 mm. ; of hind 

 femur, 4 mm. Total length of a leg of second pair, 11 mm. 



The female resembles the male in colour and markings, but is 

 larger. The first genital segment (PI. xiii., fig. 4) has a small 

 central process on its hinder edge. 



In both sexes the hairs of the fringe on the tibia and tarsus of 

 the middle pair of legs are somewhat short. 



Larva. — A good series of larvae of this species in various 

 stages has fortunately been secured ; and I hope to be able to 

 work out some details of the metamorphosis at a future time. 

 The young larva is of a nearly uniform yellowish-brown colour. 

 Later, the dark chitinous plates described by Dr. Buchanan White 

 (" Challenger." Zoology, vol. vii., No. 3, p. 72) are apparent : 

 three on the head and two on each thoracic and abdominal 

 segment (PI. xiii., fig. 8). The front femora of the immature 

 individuals are yellow for the proximal two-thirds of their length. 

 The front tarsi (as in other Halobat'es larvse) have but one joint. 



A number of specimens of both sexes were collected by 

 Professor Haddon off the shores of the island of Mabuiag. The 

 majority were obtained in October, 1888. 



This species seems quite distinct from all the known species of 

 Halobates. The female is slightly longer than the male, as well 

 as broader, and seems the largest Halobates hitherto recorded. 

 This species may be distinguished at a glance from the other 

 large species {R. ivullerstorffi, Frauenf., H. princeps, White, S. 

 flaviventris, Eschs., and H. splendens, With), by the front tarsus 

 which has its second joint nearly twice as long as the first, whilst 

 in those species the two joints are sub-equal in length. It seems 

 to resemble more nearly in structure H. hayanus, White, from the 

 Bed Sea, but is decidedly larger than the latter, and differs from 

 it in the shape of the genital segments of the male. 



