BRACHYURA. 363 



Leucosia urania, HEKBST, 1801 A. 2, p. 220. 



Locality : Galle, one specimen. 



Description: Young male, C.I. = 17'00 ; C.b. -rC.l. = 0'84. 



A series in the British Museum links this specimen witli the adult form, from 

 which latter it differs in certain points : (l) fingers are crenulate in their distal half 

 only; (2) hand is cristate on both borders (the lower crest is crenulate the 

 crenulations swollen into granules). 



Leucosia cumingi, BELL, 1855 A. 2, p. 226. 



Locality : Coral reefs, Gulf of Manaar, one specimen. 

 Description: Ovigerous female, C.I. = 13 '00; C.b. -f- C.I. = T04. 



Leucosia haematosticta, ADAMS and WHITE, 1848 A.2, p. 229. 



Localities : Aripu coral reefs, Gulf of Manaar, two specimens (6, c) ; Station I, off 

 Negombo, one specimen (a). 



Description : (a) male. (/>) ovigerous female, (c) ovigerous female. 



C.I. ...... 975 13-00 13-50 



C.b.-rC.L . . . 0-97 1-00 0-98 



Leucosia pubescens, MIERS, 1877 A.2, p. 233. 



Localities : Galle, one specimen ; pearl banks, Gulf of Manaar, three specimens ; 

 coral reefs, Gulf of Manaar, three specimens. 

 In an ovigerous female, C.I. = 18 "50. 



Philyra platychira, DE HAAN, 1841 A.2, p. 242. 



Localities : Coral reefs, Gulf of Manaar, four specimens ; pearl banks, three 

 specimens ; Trincomalee, three specimens ; Welligam Bay, two specimens ; Galle, six 

 specimens. 



An indication of sexual dimorphism is given by index Ch.l. -i-C.l. : 



For 12 adult males this has mean value 2 "32 and range of variation 2 '23-2 '40. 

 4 females T83 1 '67-1 '92. 



To this difference all the segments of the cheliped contribute. Thus 



Arm 1. + C.I. Wrist 1. -r C.I. H.I. - C.I. F.I. -r C.I. 



Male means .... -0'93 0'32 0'60 0'47 



Female means ... 071 0-26 0'51 0'35 



All have some very fine granulation on the posterior and lateral regions of the 

 dorsum of the carapace the specimens from " Coral reefs, Gulf of Manaar," have in 

 addition some rather large scattered granules on the lateral region. 



Some of the specimens fall under KLUNZINGER'S var. bidentata (K., p. 72). 



3 A 2 



