Hydrophilidcs of New Zealand. 473 



with three examples at Bedley, on the road between 

 Greymouth and Christchurch. 



Philydrus. 



I have three New Zealand species of this genus, which 

 may be thus distinguished : — 



Mesosternal lamina large 1. 



Mesosternal lamina small . . . , . , . . . . P. abditus. 



{Pitchy ; head with obscure yellow spot on each 



side in front . . . . . . . . P. tritus. 



Sordid testaceous ; the black head with large 



yellow spot on each side in front . . . . P. variolorum. 



1. 



Philydrus tritus. 



Philydrus tritus, Broun, Man. N. Z. Col., p. 78. 



Auckland and Tairua (Broun) ; Christchurch {Wake- 

 field). 



Philydrus variolorum. 



Philydrus variolorum, Broun, Man. N. Z. Col., p. 79. 



Auckland (Laivson) ; Tairua {Broun) ; Wellington and 

 Christchurch {Wakefield). 



The character from which the specific name is derived 

 is not a natural one, and will be found only very rarely 

 present ; individuals with the surface pitted occur occa- 

 sionally in a great number of species of water-beetles, 

 probably from being pressed on sand or something of 

 that sort during the metamorphosis. 



Philydi'us abditus, n. s. 



Oblongo-ovalis, parum convexus, niger, supra fusco-niger lateri- 

 bus pallidioribus, tibiis, tarsis, antennarum basi palpisque testaceis, 

 his apice summo fuscescente, capite utrinque macula parum dis- 

 tincta testacea ; corpore supra nitido, crebre sat fortiter punctate ; 

 mesosterni lamina parva. Long. 4 mm. 



The colour above is of a dilute black, getting paler at 

 the margins, with the head quite black ; I cannot detect 

 any serial punctuation amongst the diffuse punctuation 

 of the wing-cases, but very vague indications of an 

 obsolete striation can be seen here and there. The 

 maxillary palpi are comparatively short. 



This species may readily be distinguished from the 



