1913-] S.Kemp: Crustacea Stomatopoda of the Indo-Pacific Region. 147 



species observed by Brooks. l As a rule they are found in shallow water, but G. spin- 

 osissimus and G. acanthurus have been recorded from 45-50 fathoms. 



Key to the species of Gonodactylus. 



I. Mandibular palp present ; margins of inner uropod and ultimate segment of 

 outer uropod, not bearing spines. 

 A. Antero-lateral angles of carapace well in advance of rostral base ; posterior 

 margin of last abdominal somite straight or slightly convex in dorsal view ; 

 basal segment of outer uropod extending at least a little beyond inser- 

 tion of ultimate segment. 

 I . Rostrum with antero-lateral angles rounded or acute , never sharply spinous ; 

 inner uropod normal in shape and in its investment of setae [mandibular 

 palp three-segmented]. Group I. 

 A. Mid-dorsal portion of telson with three long keels, occasionally with a 

 short additional keel on either side at hinder end of median. 



1. No ridge on inner side of keel of intermediate marginal teeth of 



telson. 



a. Dorsal processes of ophthalmic somite large and subtriangular ; me- 



dian keel of telson not very strongly arched in lateral view, its 

 depth l less than half its greatest breadth ; no spinules on dorsal 

 surface of telson. 

 i. Antero-lateral angles of rostrum rounded or subacute ; a pair of 

 small round tubercles close to anterior margin of telson ; sub- 

 median dorsal keels of telson parallel, 

 a. Form narrow ; abdomen compressed and strongly arched from 

 side to side ; lateral marginal teeth of telson small but 

 distinct, rarely absent . . . . . . . . chiragra, p. 155. 



ß. Form broader ; abdomen less compressed ; lateral marginal 



teeth of telson wholly absent . . . . . . do. v. platysoma,-p. 162. 



ii. Antero-lateral angles of rostrum acute ; no tubercles near anterior 

 margin of telson ; submedian dorsal keels of telson posteriorly 

 convergent . . . . . . . . . . acutirostris, p. 163. 



b. Dorsal processes of ophthalmic somite consisting a pair of small and 



inconspicuous transverse plates ; median keel of telson very 

 strongly arched in lateral view, its depth ' 2 fully half its greatest 

 breadth ; dorsal surface of telson usually beset with spinules. 

 i. Telson broader than long ; intermediate marginal teeth well-deve- 

 loped ; dorsal surface with spinules . . . . . . demani, p. 164. 



ii. Telson as long as broad : intermediate marginal teeth rudimentary 



or absent ; dorsal surface with abundant spinules . . . . do. v. spinosits, p. 165. 



iii. Telson broader than long ; intermediate marginal teeth rudimen- 

 tary ; dorsal surface without spinules . . . . . . do. v. espinosus, p. 166. 



2. A ridge on inner side of keel of intermediate marginal teeth of telson. 



1 See addendum, p. 197, for further notes on this subject. 



8 Measured from the highest point of the median keel to the corresponding point on the lower 

 surface. 



