CHAPTER VIII. 



POLYMORPHA. 



TARSUS of legs variable. Joints of antennae clubbed or serrate. 



Family HYDROPHILIDAE. 



The family may be recognized by the curious antenna, which consists 

 of a long basal joint, the rest of the joints, except from one to three very 

 short ones, forming a club of which the apical ones are widened out and 

 pubescent. The beetles are shining black or dull in colour, the head, 

 prothorax, and elytra fitting closely together, as shown in fig. 63. They 

 are of small size. The family consists principally of aquatic forms. One 

 forest-living beetle, a species of Regimbartia, is described briefly below, but 

 I have not taken its larva. 



Regimbartia aenea, Benth. 



Habitat. Goalpara, Assam. 



Tree Infested. Sal (Shorea robusta). Kachu- 

 gaon, Goalpara. 



Beetle. Elongate-ovate. Black, with a shining yel- 

 lowish lustre. Head depressed, impressed medianly ; the eyes 



large, placed laterally, and yellowish 

 Description. in colour. Prothorax convex, de- 



pressed in front, wider than long, 



anterior margin and sides rounded ; disk smooth and very 

 finely punctate. Scutellum elongate, heart - shaped, very 

 finely punctate. Elytra elongate, very convex, depressed 

 apically, the sides rounded to posterior coxae, and thence 

 rather sharply constricted ; apices separately rounded ; very 

 FIG. 63. Regimbartia aenea, finely punctate. Under-surface dull black. Legs shining 

 Benth. Assam. black. Length, 5 mm. 



This beetle in its mature state is probably a sap-feeder. During a 



visit to the Kachugaon sal forests in Assam in May 



Life History. 1906 Mr. Perree had a large green healthy sal-tree 



felled for me on the I3th. Between the i6th and 



igth of the month this beetle was found beneath the bark of this tree 



