OCR Text |
Show 1906.] COLEOPTERA OF THE GENUS SCIOBIUS. 261 surface impressed, tricarinate, the carina? straight and parallel, the punctuation and pubescence as on the head. Antennce very long and slender, piceous, with fine grey pubescence; scape slender, subcylindrical, slightly curved and abruptly clavate, funicle with the third joint much longer than the first. Prothorax rather transverse, rounded at the base, narrower and truncate at the apex, sides slightly rounded, broadest about middle ; upper surface convex, closely set with low rounded granules, but with a more or less distinct smooth central line: colour black, the granules bare, the interstices with fine grey pubescence bearing an evanescent yellow powdering, which is denser at the sides and along the base. Elytra ovate, a little broader than the prothorax at the base, which is jointly sinuate; sides rounded, broadest rather before middle, narrower in the tf ; upper surface convex, with distinct stria?, which, according to the incidence of the light, appear to contain either rows of subquadrate punctures or rows of small granules, both of which vanish on the declivity ; intervals slightly convex, of approximately equal width and evenly raised, almost impunctate and without tubercles, with thin very fine pubescence bearing a yellowish or reddish powder, which is easily removed and is only observable at the sides and apex, but in perfect specimens it would doubtless occur all over the disk. Legs moderately long and slender, black or piceous, with fine grey pubescence; the anterior pairs of femora more strongly clavate in the S , the anterior tibia? scarcely curved interiorly and similar in the two sexes; the first joint of the tarsi broad and elongate, about as long as the next two together. T Y P E in the Stockholm Museum. NATAL : Howick (Dr. F. Dimock Brown). The unusual development of the first tarsal joint is a good distinctive character. I have seen only three examples of the species. *23. SCIOBIUS MARGINATUS Fahr. S. marginatus Fahr. op. cit. p. 28. Long, tf 8|-8i, 2 8£; lat. tf 3f, 2 H mm. Head almost as long as broad, vertex convex and finely aciculate forehead shallowly punctate and with a broad median impression ; colour piceous or ferruginous with sparse pale pubescence, forming a denser ring round the eyes, which are slightly prominent. Rostrum longer than broad, basal margin distinctly angulate, sides parallel to near apex, genai slightly and roundly dilated in both sexes; upper surface slightly impressed, distinctly tricarinate, the outer carina? parallel to near apex, then rapidly divergent, the interspaces finely rugose and with thin pale pubescence. Antennce moderate, piceous, with grey pubescence; scape subcompressed, strongly curved and gradually dilated to apex ; funicle slender, third joint longer than first. Prothorax in o* a little broader than long, truncate at base and apex, the latter narrower and broadly but shallowly constricted ; sides almost straight, broadest 18* |