MARINE CRUSTACEANS. 713 



segment which follows has on the hind margin two sub-median bosses. These are followed 

 on the telsonic segment by two slightly divergent carinae leading to two very large bosses 

 each carrying a crest of hairs. To them succeeds a large median boss. This is followed by 

 a convex-sided apically truncate process emerging beyond the convergent apices of the telsonic 

 emargination. All these parts are strongly fringed with setae, and distinguish the species 

 from C. pilosa, Milne-Edwards, which has an otherwise similar pleon, but ending in an almost 

 cylindrical median plate, rounded at the end and not reaching beyond the two lateral apices. In 

 C. aculeata, Haswell, the median plate projects beyond the lateral points, but it is differently 

 shaped, and the bosses on the pleon are arranged transversely, not in successive paii's. In 

 C. tuberculata, Haswell, the bosses are successive, but of quite different character, and the 

 apices of the terminal notch project beyond the median process. 



The eyes are wide apart, the anterior margin of the first pei'aeon-segment being deeply 

 emarginate to receive them. 



The first antennae have a large, bent, composite basal joint, with the following joint not 

 very large. To the stoutly constructed peduncle succeeds a slender flagellum of 14 joints, of 

 which the first is much the longest. In the second antennae the peduncle is not robust, 

 the fifth joint a little longer than the fourth, the flagellum 17-jointed. In the mandibles 

 the principal cutting edge is homy-looking, not dentate. The palp is rather slight. The 

 maxillipeds have the fourth, fifth and sixth joints fully lobed. As will be seen in the figure 

 the palp on one side of the specimen was in process of regeneration. The limbs of the 

 peraeon are of the character usual in this family. The male appendages of the seventh 

 peraeon-segment are rather long, not very acute. In the second pleopods the male appendage 

 is very long, with its narrow inward-curving apical part reaching much beyond the plate 

 to which it is attached. 



The uropods are straight, rather narrow, very setose, the outer ramus more obliquely truncate 

 than the inner, which it outreaches, both extending beyond the telsonic segment, the outer 

 having a prominent spine at the apex of its raised outer border. In C. Icmgistylis, Miers, the 

 inner ramus has an outward curve, and decidedly outreaches the outer. 



Length, 6 mm., breadth, 3 mm. 



Locality. Minikoi, from 5 to 7 fathoms in centre of lagoon. 



Specific name referring to the carinae on the pleon. 



Fam. Limnoriidae. 



Limnoriadae, 1850, White (part), List of British Animals in Brit. Mus., Crustacea, p. 68 

 (without definition); Limnoriidae, 1880, Harger, Rep. U.S. Fisheries, Part 6, p. 371; 1893, 

 Stebbing, History of Crustacea, p. 367 ; 1897, Sars, Crustacea of Norway, Vol. ii. Part 4, p. 74. 



The family, as restricted by Harger, still contains a single genus. 



Gen. Limnona, Leach. 



Limnoria, 1814, Leach, Edin. Encycl., Vol. vii. p. 433; 1867, Bate and Westwood, Brit. 

 Sessile-eyed Crustacea, Vol. ii. Part 18, p. 349 ; 1880, Harger, Rep. U.S. Fisheries, Part 6, 

 p. 373 ; 1897, Sars, Crustacea of Norway, Vol. ii. Part 4, p. 76. 



