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Show 390 MR. R. I. POCOCK ON A [Dec. 2, These considerations point to the conclusion that the African species of Desis made their way into the country by two routes, one lying to the north, the other to the south of the Indian Ocean. D esis c ro ssland i, sp. n. (Text-fig. 78.) $ . Colouring like that of the other species of the genus, the mandibles and cephalic region of the carapace deep castaneous; sternum and mouth-parts a little or considerably paler ; legs pale ochre, with scopular hairs on tarsi and protarsi fuscous ; abdomen testaceous. Carapace about as long as tarsus + protarsus, rather longer than patella-f-tibia of 4th leg; a little shorter than patella-f-tibia of 1st and as long as protarsus -f i the tarsus of this appendage. Eyes (text-fig. 78, A) of the posterior line slightly procurved, sub-equally spaced, the medians only a little farther apart than either is from the lateral, the medians about 2 diameters apart and perhaps 1 k diameters from the laterals ; anterior median eyes about a diameter apart and about two diameters from the anterior laterals (in other specimens the eyes appear to be larger and the distances between them consequently less). Mandibles (text-fig. 78, B ) : of the two teeth on the postaxial (posterior or outer) border of the fang-groove the distal is much the larger, the space between the two being equal to about three or four times the length of the proximal, and only a little less than the space between the distal and the base of the fang; teeth of the preaxial or inner side of the fang-groove normally seven in number, the first, situated opposite the interval between the two teeth of the outer (postaxial) row, smaller than the second, third, or fourth, which are large and progressively but only slightly Text-fig. 78. A Desis crosslandi. A. Eyes from above. B. Distal extremity of right mandible from below. C. Vulva. |