354 On Aquatic Carnivorous Coleoptera or DytisciJ(s. 



puncture. The external dark line on the wing case though very short, is generally- 

 very distinct and definite, but sometimes becomes connected with the more elongate 

 internal line. 



Arabia, Persia, Egyjit, Algeria, Southern Europe. 68. 



273. Bidessus major, n. sp. — Oblongo-ovalis, subtus niger, supra nigro testaceoque 

 variegatus, antennis pedibusque testaceis ; prothorace sparsim distincte punctato, 

 medio testaceo, basi margineque apicali fuscis ; elytris versus suturam distincte sat 

 crebre punctatis ; coxis posterioribus parce subtiliter punctatis. Long. 3, lat. 

 If m.m. 



This species is very similar to Dytiscus geminus, (No. 269), but is more than 

 twice as large, and the punctuation of the upper surface is rather coarser. 



Arabia ; Persia. 69. 



274. Hyphydrus hamulatus, Gyll., Hydroporus hamulatus, M.C. — Oblongo- 

 ovalis, opacus, testaceus, abdomine infuscato, elytris lineis duabus crassiusculis 

 fuscis, interna apice hamata, externa abbreviate ; elytris densissime fequaliter 

 subtiliter punctatis : coxis posterioribus obsolete punctatis. Long. 2, lat. 1 m.m. 



The pubescence of the upper surface is very fine but distinct ; the thorax is rather 

 closely, finely and evenly punctured, but not so densely and finely as the elytra. 



This species is excessively rare ; I am indebted to Dr. J. Sahlberg of Helsingfors 

 for the only individual I have seen. Its structure appears very similar to that of 

 Dytiscus geminus and its allies ; mj' specimen is probably a male, for the four front 

 tarsi are rather broad. 



Scandinavia, among marine Confervre. 71. 



275. Bidessus lajticulus, n. sp. — Oblongo-ovalis, nitidus, fere ItBvis, rufo-testaceus, 

 subtus lateribus infuscatis ; elytris signaturis fuscis, punctis impressis distantibus, 

 subtilibus sed distinctis ; coxis posterioribus paicissime subtiliter punctatis. Long. 

 2, lat. 1 m.m. 



The thorax is almost impunctate. The markings on the elytra are a dark 

 transverse angulated one at thejextreme base, a dark common line on the suture, a 

 longitudinal line outside the sutural one and Avhich is at its hind part thickened 

 externally, a smaller dark mark near the outer margin, and a mark near the 

 humeral angle connecting the basal mark with the others. The species much re- 

 sembles Hydroporus japonicus, (No. iJSG), but is readily distinguished by the 

 abbreviated impressions of the elytra and thorax. I see no sexual diflferences. 



Siam, (Bangkok) : Celebes, (Macassar, Jan. 1874, Beccari). 72. 



