I9I7-] S. Kemp : Notes on Crustacea Decapoda. 273 



been unaware of the existence of Stirapson's account, for he makes 

 no reference to it and his description is headed ' ' Elamene truncata 

 (nov, sp.)." That both authors have used the same specific name 

 is presumably due to a remarkable coincidence. 



Alcock was able to examine only a single example of this 

 species, but two others have since been obtained ; unfortunately 

 all three specimens are females. Both Stimpson and A. Milne- 

 Edwards note that the chelae of the male are inflated and there is 

 consequently little doubt that the species belongs to Elamena, sensu 

 stricto. As in E. sindensis, the margins of the carapace are up- 

 turned and the front, or rostrum, bears on its underside a deep 

 vertical keel, giving it a T-shaped appearance in facial view 



The abdomen of the male, according to Baker's description 

 and figure, consists of five pieces, whereas only four are to be 

 found in all the males of other species of Elamena and Trigonoplax 

 that I have seen. From the figure it looks as if only the 3rd and 

 4th segments were fused in E. truncata, in place of the 3rd. 4th 

 and 5th. A fresh examination of males is desirable. 



In the Indian specimens the carapace is proportionately 

 broader than in those described by Baker, the breadth being 

 decidedly greater than the length. The front, or rostrum is 

 squarely truncate, not rounded as described by Henderson. Be- 

 hind the base of the swollen eyestalk there is a small post-ocular 

 tooth (not shown in Baker's 

 figure) which is altogether invis- 

 ible in dorsal view. The chela of 

 the female is little stouter than 

 the walking legs ; the fingers gape 

 slightly when closed and are ,,- ^ "TT'^c-; ^ ^ 



° -^ ... . biG. 23. — tlamena truncata 



armed on their inner margins (Stimpson). 



with minute teeth and short Terminal segment of abdomen of 



hairs. The dactylus in all four female. 



pairs of walking legs is triungui- 



culate at the apex. The anterior border of the ultimate segment 



of the abdomen of the female is strongly sinuous (text-fig. 23). 



Alcock examined a single individual of this species, obtained 

 at the Nicobars. The two additional specimens were found at 

 Port Blair in the Andamans under a block of coral exposed at low 

 water; the carapace of the larger is 4-8 mm. in lengtli. When 

 alive the carapace was brown in colour with four cream-coloured 

 marks* as described by Stimpson. 



There is also in the Indian Museum, a female specimen of 

 E. truncata, unfortunately with all the legs missing, received many 

 years ago from the Godeffroy Museum under the name Elamena 

 quoyi. It bears the label "Samoa and Viti Is." 



The species appears to be one of wide Indo-pacific distribution. 

 In addition to the above records it is known from the Ceylon coast 

 (Henderson), the Loo Choo Is. (Stimpson), New Caledonia (A. Milne- 



Shown by dotted lines in text-fig'. 22. 



