-The genus Galeicles was described by Descamps (1977). He included in the genus two species. G. teocchii Descamps (as type species) and G. parvulus Descamps, both from the Central African Republic. In the present paper a new species G. kooumani is described from Chad. Galeicles kooymani sp. n. Figs. 7-9, 12,13, and 15 Type.-Holotype male. CHAD, Handa park, nr. Sarh, 23.III.1991 Kooyman Natural Hisory Museum, London (NHM) Description and Diagnosis.-MALE. Size small. Differs from G.parvulus to which it is related most closely, in slightly more slender build, more acute apex of head (compare Figs. 6 and 9) and detailed structure of external genitalic appendages (compare Figs. 7, 8 with 1, 2, and 4, 5). Lobes of last abdominal tergite smaller than those of G. parvulus. Coloration brownish, with paler areas; head and apex of abdomen with darker brown maculation. Sub-ocular spot on cheeks light brown; hind femur pale yellowish-green, hind tibiae bluish-green basally, yellowish apically. FEMALE. Exhibits rather more distinctive diagnostic features than male. Ovipositor valves shorter (Figs. 12, 13), with fewer teeth than in G. parvulus (Figs. 10,11). Tooth on upper outer apical corner of hind knee in sp.n. (Fig.15) less acute than in G. parvulus)(Fig.14). General coloration green to bluishgreen; subocular spot on cheeks a contrasting bright scarlet. Median dorsal band narrow but strong, contrasting yellowishwhite, bordered with black. Hind femora the colour of body, lunules of hind knee brown; hind tibiae greenish basally, brownish, apically. Measurements (mm).-Male: Size small, length of body 9 mm, hind femur 7x1.7 mm, pronotumn 1.8 mm long by 2.2 mm high. Female: Size nearly twice size of male length of body 1617 mm, hind femur 8x2.3 mm, pronotum 2.7 mm long x 4 mm high. Distribution.Known only from Republic of Chad, West Africa. Specimens examined.Besides male holotype all paratypes. Same data as holotype but 2 females, 23 vii 1991 Kooyman NHM Discussion.-Closely agrees with Descamps (1977) criteria of his tribe Galecleini (Afromastacinae) and the detailed description of the genus Galeicles Descamps 1977, based so far on two species G. teocchi Descamps 1977 from Central African Republic and G. parvulus Descamps 1977 from Cameroon and Zaire. The new species from southern Chad is structurally fairly close to its congeners; the principal distinction is in the much shorter length of the median lobes of the last abdominal tergite and the shape of the subgenital plate, the pattern of the lateral pronotal lobe is also distinctive. (Compare Figs 1-3b with a and c). The new species extends the recorded distribution of the genus almost to the northernmost limit of the distribution of Thericleidae in western Africa as represented by Adelothericles nigeriae Descamps, 1977 in Gombe, northern Nigeria. The new species is dedicated to its collector, Dr. Christiaan Ko yman of D.F.P.V., AGRHYMET, Niamey, Niger.