GERRIS. 179 



posterior margius, two .small linear spots on anterior area, followed 

 by a continuous central medial line, rostrum and legs pale 

 ochraceous : body beneath pale ochraceous, more or less covered 

 with silvery-grey pubescence ; a somewhat broken lateral fascia to 

 sternum, hemelytra and tarsi piceous ; antennae dull ochraceous, 

 apices of first and second joints, and the whole of the third and 

 fourth joints fuscous, basal joint longest, second, third and fourth 

 ioiuts shortest and subequal in length. 



Length 9 to 10 milllm. 



Hab. Bombay ; Bor Grhat {Dixon). — Malacca, Philippines, China. 

 Australia ; xldelaide River {Brit. Mus.). 



Some confusion has existed respecting this species. When Stal 

 described his G. discolor he wrote " Hi/drometora fossariim? Fahr.,'' 

 and in his reference to Fabricius's species in his ' Hemiptera 

 i^'abriciana' he again remarks: '■' L. diseolori, Stal, valde affinis 

 videtur. Exemplum typicum maxime mutilum,haud discribendum.'' 

 If we eliminate Wolff's description and figure (Ic. ii, p. 118, fig. 112) 

 which that writer ascribed to this species, but which certainly do 

 not agree with it, I think we may well accept Stal's doubts as to 

 the possibility of separating discolor, Stal, horn fossarum, Fabr. 



9()7. Gerris sahlhergi, I)isf. Tr. E. S. 1879, p. li>o; id. Sec. Yark. 

 Miss., Rhijnvh. p. 12, tig. 10 (1879). 



Head thickly covered with olivaceous pubescence, with a small 

 black spot on vertex ; antennte ochraceous ; pronotum ochraceous, 

 pubescent, anterior area, lateral and posterior margins, and a 

 central longitudinal line olivaceous (the central line is sometimes 

 largely ochraceous, and always ochraceous on tlie anterior pronotal 

 area) ; hemelytra brownish-ochraceous, with the veins olivaceous : 

 body beneath silvery-grey, pubescent, the central area, lateral 

 margins and apex of abdomen ochraceous ; legs ochraceous, 

 anterior femora with an outer longitudinal blackish fascia. Antennre 

 with the first joint longest, almost as long as second and third 

 joints together, which are subequal in length, fourth a little longer 

 than third. 



Length 8 to 10 millim. 



Hah. Ladiik ; Leh {Stoliczlai). 



9G8. Gerris tristan. Kirk. Rev. d'Ent. 1899, p. 88. 



Head black, with a large basal irregularly shaped dark ochra- 

 ceous spot ; antennae ochraceous, second (excluding base) and 

 third joints fuscous (fourth joint mutilated in typical specimen) ; 

 pi'onotum shining black, lateral and posterior margins luteous, an 

 ochraceous spot on centre of anterior area ; rostrum ochraceous, 

 its apex black : body beneath silvery-grey pubescent : prosternum 

 and apical abdominal area very pale ochraceous, a small central 

 black spot at base of abdomen ; hemelytra fuscous, the veins 

 darker ; legs ochraceous ; antennae with the first joint about as 



k2 



