0)1 Aquatic Carnivorous Coleoptera or Dytmcidce. 511 



703. Agabus liueellus, Lee, M.C. — " Regulariter ovalis, piceo-ferrugineus, nitidus 

 subtilissime reticulatus, elytris testaceis, sutura et vittis utrinque quatuor angustis, 

 nigris antice abbreviatis, nebulisque exterius piceis ornatis, sternis piceis." Long. 

 7x, lat. 4 m.m. 



I have seen only a single very immature female that I can refer to this species, 

 the reticulation of the elytra is much more distinct than itis in Colymbetes tseniolatus, 

 and the mesosternal groove is excessively indistinct being very narrow, and 

 obliquely perpendicular in its direction, the prosternal process short, and with the 

 sides much compressed. 



North America, (California). 763. 



704. Agabus lineatus, Gebl., M.C. — Ovalis, brevis et latiusculus, sat convexus, 

 testaceus, pectore coxisque posterioribus obscuris; elytris subtiliter sed baud 

 obsolete reticulatis, lineis 5 elongatis suturaque nigris. Long. 64, lat. 4 m.m. 



Of this species I have seen only a single immature female individual : it seems 

 very closely allied to Agabus lineellus but is shorter, and the hind coxas are shorter ; 

 the prosternal process and mesosternal grooves are similar except that the latter 

 is more horizontal (less oblique). 



Siberia. 7G4. 



705. Dytiscus didymus, 01., Agabus didymus, M.C. — Ovalis, sat convexus, sat 

 nitidus, robustus, niger, supra ajnescens, prothoracis lateribus elytrorumque epipleuris 

 ferrugineis, elytris macula didyraa pone medium versus latera, aliaque rotundata 

 apicali pallidis, antennis testaceis, pedibus piceo-rufis ; supra sublsevigatus, elytris 

 subsericantibus, obsoletissime punctulatis ; prothorace basi utrinque versus angulos 

 posteriores leviter sinuato, his subrectis. Long. 8, lat. 4| m.m. 



The male has the front and middle tarsi distinctly incrassate, and furnished 

 beneath with rather long hairs, bearing small palettes ; the claws scarcely differ 

 from those of the female. 



The species is very readily distinguished by the peculiar Dale mark near the side 

 of the elytra, which in clean specimens is always conspicuous, and is formed by 

 two small spots nearly or altogether coalesced. 



Central and Southern Europe, and Algeria, (England, France, Germany, Spain, Tangier). 769. 



