116 PERCY SLADEN TRUST EXPEDITION 



the three following segments rises into a very decided prominence, which is a little tip- 

 tilted on the seventh segment. 



The maxillipeds have the narrow anterior lobe bordered with eight well separated 

 seta). Between the lobes a fine membrane projects ending in an emargination between 

 two blunt, not widely separated, apices. This is apparently the lower lip, firmly attached 

 to the maxillipeds. 



The outer branches of the five pairs of pleopods are strongly tuberculate on both 

 margins and at least some of them on the surface, the first pair long and broad, and 

 all tending to conceal the inner branches from a dorsal view, and the lateral prolongations 

 of the segments from a ventral view. These prolongations and the inner branches except 

 in size agree much in character with the outer branches. The uropods are single-branched, 

 with the edges moderately incised. 



Male. The first antennse are three-jointed, with four short filaments on the little 

 apical joint. The second antenna? have a setule on the second joint and five short 

 filaments on the fourth, which is the apical joint. In the ventral view of the pleon 

 processes will be seen which appear to represent single-jointed pleopods. Judging by 

 the figures which Bonnier gives of the young male (Bopyrus stage), which shows such 

 processes, and of the adult male without them, in Cancricepon elegans, it may be 

 supposed that the male in our specimen is not fully adult. 



Length of female about 4 mm. 



The host was identified by Miss M. J. Bathbun as Actcea savignyi (A. Milne- 

 Edwards) in which the parasite occupied the left branchial cavity. 



Locality. Cargados Carajos, 30 fathoms. 



Gen. CANCRICEPON, Giard and Bonnier. 

 1887. Cancricepon, Giard and Bonnier, Travaux Lab. Zool. Wimereux, vol. v., 

 p. 172. 



1900. Cancricepon, Bonnier, Les Bopyrkke, p. 257. 



32. Cancricepon sp. 



To this genus I refer two specimens, one from the right, the other from the left 

 branchial cavity of a crab identified by Miss M. J. Bathbun as Pilumnus longicomis ? 

 Hilg., taken on the 18th of October, 1905, in a depth between 22 and 24 fathoms at 

 Amirante. The specimens were alike, both loaded with eggs. The one that was 

 measured only attained a length of l'5miii. The medio-dorsal upheaval is faint on the 

 fourth segment of the perason, but well expressed on the three following segments. The 

 apical lobe of the maxillipeds is rather strongly emarginate and furnished with four or 

 five setules on the concave margin. The secondary lamella) at the corners of the cephalic 

 lamina are simple, the outer the larger. The uropods are smooth. 



The preparation of these small specimens was not sufficiently successful to enable me 

 to give satisfactory figures. I have therefore abstained from giving a specific name. 



As compared with Cancricepon elegans (Giard and Bonnier), which attains a length 

 of over 9 mm., the small size of the present form adds to the probability that it is 

 specifically distinct. 



