32 



HYDROPHILID^. 



b|. Elytra, in the lateral aspect, 

 shorter in proportion to their 

 height than in II. hrevijml'pis and 

 H. griseus, the slope of their apical 

 third distinctly more abrupt. 

 Flattened part of sides of thorax 

 very narrow .... 



B. The longitudinal furrow on the head 

 not widened in front. 



a. Granulation of thorax about equally 

 strong throughout. Elytra, in the 

 lateral aspect, distinctly longer in pro- 

 portion to their height than in H. 

 viridicollis, the apical slope more 

 gradual ...... 



b. Granulation of thorax somewhat 

 more feeble on the disc than at the 

 sides. Elytra, in the lateral aspect, 

 distinctly shorter in proportion to 

 their height than in H. viridicollis, 

 the apical slope more abrupt . 



2. Thorax widest in the middle. 



A. Sides of thorax strongly granulate ; 

 size larger ...... 



B. Thorax smooth and shining, at most 

 feebly granulate at the sides 



H. GRANULARIS, L. 



{brevicollis. Thorns.) 



H. CRENATUS, Eeij. 



H. STRiGiFRONS, Thoms. 



H. LATicoLLis, Thorns. 



H. NANUS, Sturm. 



H. porculus, Bedel, Faun. Col. du Bassin de la Seine, i. 298. 

 Convex, rather broad, scarcely pubescent, testaceous or rufo-testaceous 

 above, with the elytra paler, variegated with black, under side fuscous ; 

 antennae, palpi and legs entirely red ; head with the eyes arcuate in 

 front ; thorax transverse, granulate, anterior angles obtuse, very little 

 produced, with the central intervals rather flat, and angularly dilated 

 in the middle, and the lateral ones divided ; elytra strongly punctate- 

 striate, with the scutellar series distinct ; the alternate intervals are 

 costate and entire (except the small scutellary costa) ; metasternum 

 with scattered piligerous punctures, not carinate between the coxse. 

 L. 4^-5 mm. 



First recorded from Scotland by M. Javet (Bedel. Faun. Seine, i. 

 322), and lately discovered by Mr. Newbery mixed with H. rugosus in 

 Dr. Power's collection from Balmuto, Moss Morran, Cowley and Esher, 

 and also in his own collection from Merton, Surrey ; Commander 

 Walker has recently found it near Oxford, and it has also occurred in 

 Norfolk ; Mr. Donisthorpe has taken it in the Isle of Wight, and 

 Dr. Joy at Bradfield, the Scilly Islands, and Garve, N.B. ; it is 

 probably common and mixed with H. rugosus in many of our collections. 



