HYDROPHILIDAE. 



31 



Upolu, is in my opinion certainly this species. In Sumatra, Java, Engano, the 

 Mentawei Is. and Indo-China, it is (as has already been pointed out by me *) 

 represented by a smaller form, D. seriatum Knisch (Regimbart in litt.), in all 

 probability not specifically distinct from D. subquadratum Fairmaire. 



3. Noteropagus politus d'Orchymont, 1919. 



Eight specimens. Tutuila : Pago Pago, 21.ix.l923, in rotten bark ; Leone 

 Road, 7.ix.l923 (Swezey and Wilder). 



These specimens make an approach to the Indo-Chinese form, N. punctatus 

 m., but the oblique rows of punctures on the sides of the elytra are composed 

 behind of somewhat larger pits, and the interstitial puncturation of the elytra 

 has no tendency to be arranged in a single row posteriorly, between the normal 

 series of punctures. 



HYDROPHILINAE. 



Tribe: HYDROBIINAE. 

 Subtribe : Helocharae. 



4. Enochrus (Lumetus) ? tritus Broun. 



A specimen from Upolu, Tafua Volcano, 1917 (Dr. H. Swale : in coll. Brit. 

 Mus.), perhaps a as the claws are not hooked, seems very near to, if 

 not identical with, E. tritus Broun, of New Zealand. The prefrons before the 

 eyes has only a faint median infuscation behind, but, since Broun recorded a 

 paler, less common variety of E. tritus, this differentiation may be imputed to 

 individual variation. The larger punctures of the sides of the pronotum are 

 hardly discernible, and the last ventral segment has a deep ciliated notch at 

 the tip. As in E. tritus, the mesosternal process forms a very thin and large 

 lamina, nearly perpendicular on its anterior side, and with a very minute 

 acumen at its anterior angle. 



This is a suitable place in which to express the opinion that the New 



* A. d'Orchymont, " Notes on Philippine Hydrophilidae " : Philippim Journ. Sci., Vol. 30, 

 p. 366, July 1926. 



