PROC. ENTOMOL. SOC. WASH. 92(3), 1990, pp. 411-415 A NEW SPECIES OF WATER SCAVENGER BEETLE, GUYANOBWS SIMMONSORUM, FROM BRAZIL (COLEOPTERA: HYDROPHILIDAE) Paul J. Spangler Department of Entomology, National Museum of Natural History, Smithsonian Insti-tution, Washington, D.C. 20560. Abstract.— \ new species of water scavenger beetle, Guyanobius simmonsorum. from a tributary of the Rio Xingii in the state of Para, Brazil is described. The beetle is illustrated by pen and ink drawings and SEM micrographs and is distinguished from the only other species described in the genus, Guyanobius adocetus Spangler. Key Words: Hydrophilidae, Guyanobius simmonsorum, new species, water scavenger beetle, Brazil The genus Guyanobius was described for the single species, G. adocetus Spangler (1986) from Guyana. This second species of Guyanobius was collected in Brazil short-ly after the description of the genus was pub-lished and is described to further define the genus. The specimens of this new species were collected from a small shaded tributary of the Rio Xingii where it flows through a lowland tropical rainforest in the Brazilian state of Para. The specimens were collected during a biological survey of the area in ad-vance of the construction of a hydroelectric dam on the river. If the dam is constructed as planned, the habitat from which this new species was collected will be inundated. Guyanobius simmonsorum, New Species Figs. 1-11 Holotypcc?. — Form and size: Hemispher-ical, strongly convex dorsally (Figs. 1, 2). Length, 2.98 mm; greatest width, 2.24 mm. Color: Shiny black dorsally except narrow band on anterior margin of head, lateral margins of pronotum, and ver\' narrow lat-eral margins and posterior half of sutural margins of elytra dark reddish brown. Ven-ter light reddish brown except metastemal disc and middle of abdominal segments 1 and 2 slightly darker reddish brown. Head: Very finely, sparsely punctate; dis-cal punctures separated by 4 to 8 times puncture diameter; punctures across base of head between eyes smaller and sparser than discal punctures and separated by 3 to 4 times puncture diameter. Clypeus (Fig. 4) strongly, broadly expanded anteriorly and laterally, concealing labrum (Fig. 4); lateral margin extending deeply into eye; anterior margin feebly arcuate apicomedially. Men-turn shallowly concave, moderately broad and moderately emarginate apicomedially; surface moderately coarsely, densely punc-tate; punctures separated by 3 to 5 times puncture diameter. Submentum shallowly concave and densely, finely punctate; each puncture bearing a seta. Thorax: Pronotum widest at posterior third; strongly rounded laterally; shallowly emarginate apically and feebly arcuate ap-icomedially (Fig. 1); truncate posteriorly; narrowly rimmed laterally and anterolat-erally behind eyes; not rimmed posteriorly except at posterolateral angles; sides nearly
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