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r 
348 On Aquatic Carnivorous Coleoptera or Dytiscide. 
252. Bidessus insignis, n. sp,—Ovalis, latus, subtus convexus, capite thoraceque 
rufescentibus, elytris testaceis, basi plagaque magna irregulari, pectore abdomineque 
nigricantibus, antennis pedibusque testaceis; thorace crebre, basi fortius, punctato ; 
elytris striis duabus suturalibus abbreviatis punctorum impressorum, plica discoidali 
ultra medium ducta sat elevata, preetereaque subobsolete punctatis; coxis 
posterioribus punctis magnis. Long. 2%, lat. 1) m.m. 
This species by its form and sculpture suggests itself as a connecting link between 
the very dissimilar Dytiscus geminus (No. 269) and Hydroporus bicarinatus, (No. 247). 
There seems to be scarcely any difference between the sexes. 
Western Arabia, (Hedjaz). 1131. 
253. Bidessus (Anodochilus) maculatus, Bab, Tr. Ent. Soc. Lond. III, 1841, p. 16.— 
Brevis, sine pubescentia, rufo-testaceus, elytris fuscis, indeterminate testaceo-signatis ; 
prothorace brevi, fere impunctato, basi plicula utrinque fortiter elevata, inter 
pliculas canalicula profunda transversa; elytris sat crebre, fortiter, iregulariter 
subseriatim punctatis, crista tenui elongata; subtus pectore abdomineque basi 
utrinque grosse punctatis. Long. 2, lat. 1$ m.m. 
Brazil, (Santa Rita, Aug., 1850, Sahlberg). 128. 
254. Hydroporus exiguus, Aubé, Spec. p. 490.—Brevis, sine pubescentia, rufo-testa- 
ceus, elytris obscurioribus indeterminate fusco-maculatis ; prothorace brevi, fere im- 
punctato, lateribus rugulosis, basi utrinque pliculafortiter elevata, inter pliculas canali- 
cula profunda transversa; elytris crebre fortiter punctatis, crista tenui elongata ; 
subtus pectore abdomineque basi utrinque grosse punctatis. Long. 153, lat. 1 m.m. 
Closely allied to Bidessus maculatus, but rather shorter and broader, and with 
the elytra a good deal more regularly and evenly, and not so coarsely punctured. 
United States of North America. 136. 
Group 4, 
255. Hydroporus cinctellus, Lec., M.C.—Oblongo-ovalis, fere sine pubescentia; sat 
nitidus, ferrugineus, capite elytrisque infuscatis, his fascia interrupta sub-basali, 
sionaturaque ante-apicali testaceis ; thorace crebre evidenter punctato, elytris et coxis 
crebre fortiter punctatis ; antennis fusco-testaceis. Long. 2, lat. 13 m.m. 
North America. 137. 
256. Hydroporus pictodes, n. sp.—Sat latus, ovalis, convexus, subtilissime et 
omnium brevissime pubescens, vix nitidus, piceo-rufus, thorace testaceo, basi late 
