igo Records of the Indian Museum. [Vol XXIV, 



specimen preserved in formalin and I have myself (loc. cit., 1916) 

 given a brief account of the colouration of the species when des- 

 cribing a Hippolytid which is also associated with Discosoma. 



The following colour description was drawn up from an oviger- 

 ous female obtained in the Gulf of Manaar : — 



The entire prawn, except for certain pigmented areas noted 

 below, was almost completely transparent. The colouration of tin- 

 ventral side could clearly be seen in dorsal view and the nerve- 

 cord was distinctly visible. On the upper side of each eyestalk 

 there was a white stripe which was continuous from side to side 

 beneath the base of the rostrum. There was a large pure white 

 patch on either side of the carapace and the gonad and associated 

 organs were invested with a membrane covered with large closely- 

 set white spots, clearly visible in dorsal view. 



The hepatic regions and lower muscular portions of the cara- 

 pace were dull Venetian red. On the sides of each of the first 

 three abdominal somites there was a large oval patch of glistening 

 white, heavily outlined in black, which extended on to the sternum, 

 and there was a broad band of the same colour on the posterior 

 edge of the last abdominal somite and on the anterior half of the 

 t'elson and uropods. In the latter half of the telson and of each 

 uropod there was a brilliant eyespot ; that on the telson was light 

 orange bordered with black, while that on each uropod was similar, 

 but with the orange centre shading distally to dark purple. All 

 the other appendages, except the pleopods, were strongly suffused 

 with blue, which was specially dark at the distal ends of the merus, 

 carpus and palm of the second legs and formed a transverse band 

 across the ringers. The cornea was grey and the eggs sage green. 



It is evident from other notes, made by Col. Alcock on Gt. 

 Coco I. and by myself at Port Blair, that there is very considerable 

 variation in colour. The white patches on the abdomen were 

 outlined in black in the specimen described above; but, just as 

 frequently, they are bordered with orange, deep blue, or, according 

 to Coutiere, pale violet, while the eyespots in the tail-fan may be 

 yellow in the centre, verging to red at the periphery and circums 

 cribed with deep red-brown. In the distribution of the pigment, 

 however, there appears to be little variation in specimens of the 

 same sex and age. 



Males lack the two white spots on the carapace and the mem- 

 brane which invests some of the internal organs is without pig- 

 ment. In young specimens the pigmentation is less well developed 

 than in adults. 



The appearance of this magnificently coloured prawn crawling 

 and swimming in the immediate vicinity of the anemone is a sight 

 not readily forgotten. That the colouration is in no degree protec- 

 tive is evident from the above description. The large white patches 

 render it very conspicuous and I have already (loc. cit., 1916) drawn 

 attention to the remarkable fact that similar white patches or 

 bands are a characteristic feature of the colour pattern of a Hippo- 

 lytid and two species of fish which are also associated with Disco- 



