138 Memoirs of the Indian Museum. [Vox,. IV, 



1. The rostrum is quadrilateral, with the sides distally convergent and the an- 



terior margin straight. 



2. The eyes, according to White's figure, are much larger, the breadth of the 



cornea being about one-third the length of the carapace excluding the 

 rostrum. 



3. The dactylus of the raptorial claw is much less strongly dilated at the base, 



but otherwise resembles that of 0. scyllarus. 



4. There are only six carinae on the sixth abdominal somite, the inner interme- 



diate pair found in the preceding species being absent. 



5. The median crest of the telson is very remarkably elevated ; its height above 



the general surface is nearly equal to the breadth between its base and the 

 lateral margin. The submedian carinae are entire ; the submedian spines are 

 less expanded at the base than in 0. scyllarus and their movable tips appear 

 to be larger. 



6. The basal segment of the outer uropod is, according to the figure, only about 



two-thirds the length of the distal segment ; there are only eight or nine 

 movable spines on its external margin. 



Lanchester notes that in his specimen the rostrum does not nearly reach the base 

 of the eyestalks as it appears to do in White's figure. Even in the latter a greater 

 portion of the ophthalmic somite is exposed than in 0. scyllarus. 



White remarks that in his dried specimen the greater part of the upper surface is 

 tinged with a reddish hue, while along the middle of the back there is a pale line. 



0. cultrifer is known only from two examples, 4 and /\\ ins. in length. One is 

 recorded from China (White, Miers) and the other from Kelantan in the G. of Siam 

 (Lanchester). 



3. Odontodactylus carinifer (Pocock). 



1893. Gonodactylus carinifer, Pocock, Ann. Mag. Nat. Hist. (6), XI, p. 478, pi. xx B, figs. 4. 4a, b. 



1894. Odontodactylus carinifer, Bigelow, Proc. U.S. Nat. Mus., XVII, p. 496. 



0. carinifer is known only from a single small specimen which is distinguished 

 from the two preceding species by the following characters : — 



1. The rostrum is semicircular, not quadrilateral or cordiform. 



2. The eyes are extremely large, according to Pocock' s figure the breadth of the 



cornea is exactly half the median length of the carapace excluding the 

 rostrum. 



3. The dactylus of the raptorial claw is moderately dilated at the base and is 



armed along its inner margin with three sharp subequal teeth in addition to 

 the spinous termination. 



4. The sixth abdominal somite bears six carinae only, as in 0. cultrifer. The 



telson also resembles that of this species, but the median crest is only half 

 the height, and the seccrd lateral carina, found in the two preceding species 

 running to the apex of the lateral marginal teeth, is absent. 



