Water-beetles. 9 



moderate in size. In the male there is an extremely minute, 

 scarcely perceptible depression at the tip of the last ventral plate. 

 Twelve specimens in backwater near the river north of Gebel 

 Ahmed Agha, eight on waterplants, Grebel Ahmed Agha. 



26. Amphiops abeillei Guill. (Bull. Soc. ent. France 1896, 

 p. 229). 



This species was described from two specimens, the locality 

 given being Egypt. I have a series in my own collection found 

 by Millingen in Egypt, and these specimens do not differ from 

 the series before me from the "White Nile. The species varies 

 somewhat in size, colour and punctuation. One specimen, of 

 small size, is of a pale ferruginous colour, and has the scutellum 

 a little shorter, so that it may perhaps prove to be another species. 

 White Nile, several localities. The doubtful specimen was found 

 North of Kaka on the 12 th March. 



Three specimens among waterplants on the shore S. of G-oz 

 Abu Gomr; five in backwater near the river north of Gebel 

 Ahmed Agha; two on waterplants, Gebel Ahmed Agha; four 

 north of Kaka. 



27. Ochthebius niloticus n. sp. Fusco-testaceus, capite tho- 

 raceque metallescentibus, fere impunctatis; elytris fortiter punc- 

 tato-striatis, inters titiis angustis. Long. 1 7 / 8 mm. 



This species is extremely closely allied to the European 

 0. marinus Payk., but has shorter palpi and the punctures on 

 the elytra are larger so that the interstices are narrower. 0. cri- 

 meae Kuwert has paler elytra and deeper impressions on the 

 thorax. The legs in 0. niloticus are dusky testaceous. 



38 specimens from a pond rich with algae near Giseh, Cairo. 

 December 1900. 



28. Hydrochus niloticus n. sp. Parvus, supra metallescens, 

 fortiter punctatus, elytrorum interstitiis haud elevatis, prothorace 

 fere inimpresso; palpis pedibusque flavis, femoribus anterioribus 

 vix, posterioribus bene infuscatis. Long. 2*/i mm - 



One of the smallest insects of the genus, and with the upper 

 surface unusually even, there being no elevation of any of the 

 elytral interstices, and only slight traces of the usual central 



