Coelometopon cavifrons Janssens

Perkins, Philip D., 2005, A revision of the African hygropetric genus Coelometopon Janssens, and description of Oomtelecopon new genus (Coleoptera: Hydraenidae), Zootaxa 949 (1), pp. 1-103 : 1-103

Coelometopon cavifrons Janssens

(Figures 49, 50, 86)

Coelometopon cavifrons Janssens, 1972: 390 .

Type Material. Holotype (male): Tanzania, Uluguru Montains, "Morning Side"; deposited in the MRAC. [labels: HOLOTYPUS //Tanzanie: Mts Uluguru Morning Side , alt. 1600 m. 21–29/VI/71 sur roche ruisselante// Coll. Mus. Tervuren Mission Mts Uluguru L. Berger, N. Leleup J. Debecker V /VIII/71// Prép. Micr. No 711012.1// E. Janssens det., 1972 Coelometopon cavifrons n. sp. //DIGITAL IMAGE captured 2004 P. D. Perkins]

Diagnosis. Recognized by the contrasting reddish­brown dorsum with piceous elytral punctures, the non­granulate and shining odd­numbered elytral intervals, and, in males, the midlongitudinal ridge on the clypeus (Fig. 49).

Description. Size (length/width, mm x 100) holotype: body (length to elytral apices) 2.50/1.15, head 0.50/0.71, pronotum 0.56/0.96, elytra 1.59/1.15. Head, pronotal disc and elytral serial punctures piceous, remainder of dorsum and legs reddish brown.

Frons with large non­granulate areas, granules near margins, near ocelli and forming midlongitudinal row of about five granules in anterior 1/2; anterior margin markedly concave. Clypeus raised in prominent midlongitudinal ridge; setose at margins; non­granulate except narrowly at base. Granules of frons and pronotum similar in size. Labrum small, set beneath margin of clypeus, lobes small, triangular in ventral aspect. Maxillary palpi small, ca. 3/4 width of anterior margin of clypeus, last three articles subequal in length, last article suboval. Mentum with two depressions.

Pronotum with non­granulate areas on disc; sides straight or weakly arcuate in front of and behind widest part; lateral depressions very wide, strongly granulate at lateral margin, otherwise almost entirely non­granulate, shining; large, deep, oval fovea posteriorly. Median groove deep and wide, tapering slightly posteriorly, margined by sharp, granulate ridge; interior of groove granulate in anterior and posterior depression, shining and nongranulate in middle part; two low, granulate callosities on each side of median groove.

Elytral serial punctures large and deep, very discrete due to color contrast with intervals. Elytral intervals: even numbered intervals with long granulate callosities, all mostly similar in height, 3 on 2nd, 4 on 4th, and ca. 5 on 6th, inter­callosity areas smooth, shining; odd­numbered intervals non­granulate, shining but undulating in part due to deep serial punctures, except 7th with small granulate callosity just behind humeral angle; lateral margin in dorsal aspect formed by granules on raised 8th interval (pseudoepipleuron).

Prosternum with low midlongitudinal carina. Mesosternal process transverse, narrow, anterior face concave. Metasternum strongly carinate behind mesocoxae; midlongitudinal fovea in basal 1/2 narrow, deep; disc on each side of fovea sparsely finely punctate, strongly shining; lateral 1/3 very coarsely densely punctate; posterior margin depressed in front of metacoxae. Abdomen with intercoxal sternite and adjacent part of first ventrite conjointly deeply concave; first ventrite carinate behind metacoxae; intersegmental areas deeply impressed. Females unknown.

Aedeagus length ca. 0.64 mm; flattened and distorted by microslide mounting, hence relationships of parts obscured; distal area enlarged, membranous process spinose, large, expandable; parameres joined near base of mainpiece (right paramere missing on microslide), attaining proximal part of enlarged complex distal area. The drawing I have made is from the underside view of the microslide mount (Fig. 50).

Distribution. Currently known only from the type locality in the Uluguru Mountains of Tanzania (Fig. 86).