1900.] FROM SINGAPORE AiTD MALACCA. 753 



one like that which supplied specimens of 0. ceratoplithalma, but 

 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. S 3325 x 30-25. rf 32-75x31. $ 35-5x30-5. 



Breadth taken from epibranchial angles. 



XL VI. Genus Uca Leach. 



74. Uca 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. 

 ft. 1-4 (1888) ; id. Zoolog. Jahrb. Bd. viii. p. 573 (1895). 



Hub. 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 the 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 : — 3 13-75 x 9-5. <S 28 x 18. <$ 16*5 

 Xll. 2 23-5x16. 2 19-5x13-5. 2 17-5x12. $ 17x12. 

 2 16-5x11-5. 



(b) Malacca forms :— tf 20-5 x 12. tf 20 x 12. J 19 x 11-75. 

 cJ 18x11. d 17-25x10-75. 



75. Uca dussumieei M.-Edw. 



Gelasimus ditssumieri, 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. ft. 2-7 f 1888) ; 

 id. Zoolog. Jahrb. Bd. viii. p. 576 (1895). 



Hub. 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 28x17-5. <$ 28x17-5. J27xl7'5. tf 22x14-5. 



