On Aquatic Carnivorous Coleoptera or Dytiscida. 381 



341). Hyphydrus japonicus, Sharp, Tr. Ent. Soc. Lond. 1873, p. 54. — Ovalis, 

 latus, convexus, testaceus, thorace basi, elytrisque fusco-signatis, vertice maculis 

 duabus parvis fuscis ; elytris stria discoidali ad basin sat distincta, sutiirali 

 subobsoleta. Long. 43, lat. 3 m.m. 



Mas, nitidulus, crebre inoequaliter punctatus, tarsorum quatuor auticorum 

 articulo basali posterius valde (prsesertim intermediorum) dilatato, abdominis 

 segmento basali medio tuberculo crasso subelevato. 



Fern., pedibus paulo magis gracilibus, 



(a.) ut in mare nitidula subtilius punctata ; paulo minor. 

 (b.) opaca, obsolete punctata ; evidenter minor. 



In this species the sculpture of the elytra consists of large and small punctures 

 mixed together, the large ones are rather numerous and are conspicuously diiferent 

 in size from the smaller ones, which are very fine ; the ground colour in this species 

 is a peculiar clay yellow, on which the dark markings are displayed in a very con- 

 spicuous manner. 



Japan. 40. 



350. Hyphydrus frontalis, n. sp. — Ovalis, latus, convexus, nitidus, confertim, 

 fortiter, inaequaliter punctatus, ferruginous, vertice maculis duabus minutis et 

 prothorace basi medio fuscis ; elytris testaceis fusco-signatis, stria discoidali ad 

 basin sat distincta, suturali subobsoleta. Long. 4i, lat. 3 m.m. 



Mas, tarsorum quatuor anticorum articulo basali posterius valde (prsesertim 

 intermediorum) dilatato, abdominis segmento basali medio vix tuberculato. 



Fern., paulo minor, pedibus paulo magis gracilibus. 



This species is much allied to the H. japonicus, but the ground colour is redder, 

 and the punctuation is rather coarser, which is especially to be remarked when the 

 fine punctures of the elytra in the two are compared ; the basal segments of the 

 hind body are finely punctured on the middle. 



Japan. 41. 



351. Hyphydrus Iseviventris, n. sp. — OvaHs, latus, convexus, nitidus, sat confertim, 

 iniBqualiter punctatus, punctis majoribus (elytrorum) conspicuis, ferruginous, 

 prothorace basi medio elytrisque fusco-signatis, his stria discoidali ad basin sat 

 distincta, suturali fere omnino nulla ; abdomine medio laevi, impunctato. 



Mas, tarsorum quatuor anticorum articulo basali sat dilatato ; major. Long. 5, 

 lat. 3i m.m. 



Fern., pedibus paulo magis gracilibus, minor. Long. 4^ m.m. 



In this species the large punctures of the elytra are strongly developed so as to 

 be in conspicuous contrast with the finer ones : though extremely similar to H. 



3 D J 



