112 PERCY SLADEN TRUST EXPEDITION 



1893. Kepon, Stebbing, History of Crustacea, Internat. Sci. Ser., vol. lxxiv., p. 412. 

 1900. Cepon, Bonnier, The Bopyridae, p. 250. 



1906. Grapsicepon, Giard, Comptes rendus Soc. de Biologie, vol. lxi., p. 704. 

 Dec. 22, 1906. 



Several other references will be found in the late M. Bonnier's great work above 

 cited. 



The species which I venture to assign to this genus agrees with Kepon typus, 

 Duvernoy, but not with Cepon' 1 . naxice, Bonnier, in having no medio-dorsal protuberances 

 on the perseon. In the pleon the first five segments have prolonged side-plates and cany 

 double-branched pleopods, all of tuberculate foliaceous character, and the single-branched 

 uropods have a similar appearance, all these points showing agreement with the type- 

 species. On the limbs Duvernoy could not perceive any finger, but rightly surmised 

 that it was not really absent. 



27. Kepon halimi, n. sp. (Plate 10 c.) 



The typical species, derived from an unknown crab of Mauritius, since identified as 

 Grapsus strigosus (Herbst), offers scarcely any points for exact comparison with the 

 present form. The size, however, differs very considerably. The adult female of Kepon 

 typus attains a length of 12 mm., whereas the specimen here dealt with measured only 

 about 3 mm., or at full stretch might have been 4 mm. long. The head, however, was 

 forced towards the pleon by the enormous globe of eggs in the marsupium, in such a way 

 that the earlier peraeon segments were not dorsally visible. This condition of affairs, 

 while introducing a difficulty into the measurement, made it fairly certain that the female 

 was fully adult. The lateral bosses of the early perseon segments, though large, do not 

 show that peculiar verrucosity described by Duvernoy, on which Bonnier lays stress as an 

 exceptional character of much importance, and the existence of which has been recently 

 endorsed by Giard. 



In the present species the limbs of the perceon are all provided with a small apical 

 seventh joint or finger as usual. The fifth peraeopod is rather remarkable from the shape 

 of the second joint, the front margin of which is produced into a large oval excrescence 

 above and a small circular one below. This limb on the left side (right of ventral view) 

 was lying closely adpressed to the pleopods, bearing a puzzling resemblance to one of 

 their branches. In Evgyne henclersoni (Giard and Bonnier) the fifth peraeopod has an 

 oval excrescence on the lower part of the front margin. The maxillipeds have the narrow 

 apical lobe common to all the neighbouring genera. It showed no setules. The secondary 

 lamellae of the cephalic lamina are small, sub-equal, almost simple. 



The male, which according to Bonnier has not hitherto been recognised for this genus, 

 was enclosed along with the eggs in the last marsupial plate of the female of this species. 

 In shape it agrees with that figured for Cancricepon elegans (Giard and Bonnier) except 

 that I could not see any medio-ventral bosses. The eyes are dark and reniform, much 

 longer than wide. I could not make out more than two joints in the first antennae and 

 four in the second, but a minute apical joint might in each case be present. 



Locality. This species was taken from the left branchial cavity of Halimus sp. nov. $, 

 as identified by Miss M. J. Rathbun, at Cargados Carajos, 30 fathoms. 



