Water-beetles. y 



22. Helochares niloticus n. sp. Ovalis, latus, supra sat nitidus, 

 crebrius sat fort iter punctatus, rufescens, elytris parum discrete 

 nigro-lineatis ; palpis rufis; subtus cumque femoribus niger, tibiis 

 tarsisque rufis. Long. corp. l 1 ^, lat. 4, long. palp. max. vix 

 2, mm. 



Eeadily distinguished from H. filipalpis by the colour of 

 the upper surface, the less effaced punctuation, and the shorter 

 palpi. The notch of the last ventral plate is shallow and nearly 

 filled by the ciliae with which it is set. 



This species is very close to one in my collection from 

 Madagascar, named by Mulsant "Hydrobius griseus Dej.", and 

 by Castelnau "Helochares sublineatus". H. niloticus has however 

 the punctuation of the upper surface much less effaced. The 

 Madagascar species has not, I believe, been described. 



Grebe! Ahmed Agha; on waterplants, March 1901. Three 

 specimens in very bad preservation. 



23. Helochares dispar n. sp. Pallide testaceus, subtus fusco- 

 testaceo variegatus; politus, parce obsolete punctatus, elytris lineis 

 angustis nigricantibus ornatis. Long. 3 mm. 



One of the smallest insects of the genus, readily distin- 

 guished by the pallid yellow colour, polished surface, and the 

 numerous narrow black lines on the elytra. The punctuation 

 on the head and thorax is very fine but quite distinct, but on 

 the elytra it can scarcely be detected: the black lines leave the 

 lateral and apical margins yellow. The undersurface is not so 

 much infuscate as it is in most of the other species; the troch- 

 anters and coxae are pale, and the abdomen has pale marks at 

 the sides and sometimes at the tip. 



Four specimens in backwater near the river, White Nile, 

 North of Gebel Ahmed Agha; two specimens, G-ebel Ahmed Agha. 



24. Helochares squalidus n. sp. Dilute testaceus, corpore 

 subtus cum femoribus nigris ; elytris crebre, minus fortiter punc- 

 tatis, haud profunde striatis. 



This species belongs to the subgenus Graphelo chares Kuwert, 

 and is closely allied to H. melanophthalmus (Kuw.), but it is paler 

 in colour, with finer punctuation and striae. When the elytra 

 are expanded, they exhibit the dark marks that exist in the allied 



