OCR Text |
Show 1900.] EUOM SINGAPORE AND MALACCA* 753 one like that which supplied specimens of 0. ceratophthalma, part of a small bay, and further protected by an expanse of the mangroves which grow out into the sea on many of the islets round Singapore. Dim. d 33-25x30-25. d 32-75x31. $ 35-5x30-5. Breadth taken from epibranchial angles. XLVI. Genus UCA Leach. 74. U C A ACUTA Stimpson. Gelasimus acutus, Stimpson, Proc. Ac. Nat. Sci. Philad. p. 99 (1858); de Man, Mergui Crust, p. 113, pi. vii. ff. 8-9, pi. viii. ff. 1-4 (1888); id. Zoolog. Jahrb. Bd. viii. p. 573 (1895). Hab. Singapore: Malacca, from mangrove-swamps near the edge of the sea. From Malacca there are five males ; from Singapore three males, six females and two young examples. The difference in coloration between these two sets is interesting. The Malacca specimens have their carapace of a light blue-green colour, and the external surface of the hand rose-coloured : in those from Singapore the carapace is a fine purple, with, in most cases, two light blue spots on each side of the gastric region, and tbe hands externally are of a deep plum-colour. In one or two of the females the purple of the carapace becomes mottled in front with green, this colour tending to replace the former. The Singapore specimens were obtained from the same place as the next-described species ; which is interesting, in view of their close relationship to each other. Dim. (a) Singapore forms:-d 13-75x9-5. d 28x 18. d 16*5 xll. $ 23-5x16. $ 19-5x13-5. $ 17-5x12. $ 17x12. $ 16-5x11-5. (o) Malacca forms :- d 20-5 x 12. d 20 x 12. d 19 X 11-75. d 18x11. d 17-25x10-75. 75. UCA DUSSUMIERI M.-Edw. Gelasimus dussumieri, M.-Edw. Ann. Sci. Nat. ser. 3, t. xviii. p. 148, pi. iv. f. 12 (1852); Kingsley, Proc. Ac. Nat. Sci. Philad. p. 145 (1880); de Man, Mergui Crust, p. 108, pi. vii. ff. 2-7 (1888) ; id. Zoolog. Jahrb. Bd. viii. p. 576 (1895). Hab. Singapore : from the shore on the mouth of a small river. Seven males and thirteen females. Colour of females, when alive, a rich blue over the carapace, a light sky-blue on the legs; the males a more sombre brown or bronze; lower half of hand, and index, orange; upper half, and dactyl, nearly white. In some cases the females were ornamented with one median, or one median and two lateral, fair-sized white spots in the gastric region. The interest of the colour-marking here lies in the fact that the gay colours appear in the females ; and not in the males, as is generally the case (cf. Darwin's ' Descent of Man,' 2nd ed. 1894, p. 271). Dim. d 28 x 17-5. d 28 x 17*5. d 27 x 17"5. d 22 x 14-5. |