363 On Aquatic Cainivorous Coleoptera or Dytiscida. 
short impressed stria at the base of the elytra. It varies a little in colour and size, 
some individuals having the hind body and breast infuscate. The length of the striga. 
also varies a little, it is sometimes so abbreviated as to be scarcely perceptible. 
Atlantic States of North America: “from Lake Superior to Florida,” Crotch. 131. 
321. Hydroporus pullus, Lec., M.C.—Elongato-ovalis, nitidulus, tenuissime 
pubescens, testaceus, elytris vittis elongatis fuscis tribus, crebre distincte punctatis ; 
coxis posterioribus pectoreque impunctatis, nitidis. Long. 2, lat. 1 m.m. 
In this species the apical ventral segment is a good deal broader and larger than 
in its allies, and by this character it may readily be distinguished from varieties of 
other North American species which resemble it in appearance: it has moreover 
an indistinct dorsal stria extending about half the length of the wing-case. The 
tarsi are rather long and slender, but I see no differences between the sexes. 
North America, (Red River, Pennsylvania, Louisiana). 134. 
322. Hydroporus granarius, Aube, M.C.—Breviter ovalis, Jatus, subtus convexus,. 
subtiliter pubescens, nitidus, ferrugineus, elytris obscurioribus ; prothorace obsolete 
punctato, elytris crebre distincte punctatis; coxis posterioribus nitidis, sparsim, 
subtiliter sed distincte punctatis ; abdomine fere impunctato ; antennis fuscis, basi 
testaceo. Long. 14, lat. 1 m.m. 
This species has the form of a minute Hyphydrus, the elytra continuing the 
outline with the thorax. I see no sexual characters among the five specimens I 
have examined, all of which have the tarsi small and rather slender. 
United States of North America, (Massachusetts). 140. 
323. Bidessus lynceus, n. sp.—Brevis, ovalis, fere sine pubescentia, nigricans, 
capite fusco, prothorace ad angulos anteriores late testaceo, elytris fasciis duabus, 
transversis, flammulatis, testaceis; prothorace basi et disco punctatis; elytris 
erebrius sat fortiter, pectore fortiter, punctatis; antennis testaceis, apicem versus 
plus minusve infuscatis. Long. 2, lat. 13 m.m. 
The male has the upper surface a little shining, the anterior and middle tarsi 
are but little dilated: in the female the upper surface is dull. 
The species is allied to Hydroporus cinctellus, Lec. (No. 255) but it is a good 
deal broader and shorter, and the fascize on the elytra are very irregular, being 
irregularly angulate; these yellow marks are variable in their extent, sometimes. 
occupying nearly half the surface of the wing-cases, and at other times diminished 
in size, and broken into more or less separated marks. 
Central America, (Guatemala City, E. C. Champion). 1129. 
