224 



— Dorsal denticles present only on pereon somites III-VII. Anterior 

 distal angle of 2nd segment of pereopods V produced into two long 



slender processes, of which one may be weakly developed 



1 . C. brevicaudata Wagl. 



2. Second segment of pereopods V denticulate on anterior margin and 



anterior distal angle produced into a large notched lobe 



2. C. tenuis Wagl. 



— Second segment of pereopods V not denticulate on anterior margin, 



its anterior distal angle produced into simple curved process 



3. C. macrocarpa (Chevr.). 



1. Ctenoscina brevicaudata Wagler, 1926 (Fig. 94) 



Wagler, 1926: 435; Vinogradov, 1957: 218, 1962: 18. 



Length of sexually mature specimens about 4 mm. 



Dorsal denticles are present on pereon somites III-VII, pleon 

 somite I-III, and on urosomite I; these denticles (except the urosomal) are 

 weakly denticulate on the anterior margin. The head has long, forwardly 

 directed spines, which are located under antennae I. 



Antennae I are armed on the outer edge with strong spines, and 

 reach the length of the pereon. Antennae II are absent in both males and 

 females. Maxillae I and II are scinoid in form; each lobe of maxillae 11 

 terminates in two spines. The maxillipeds have broadly oval outer lobes 

 with one apical seta each; the inner lobes are in the form of a small 

 tubercle or totally imperceptible. 



Coxal plates II-V taper anteriorly and posteriorly. 



Pereopods I have a chela formed by the prolonged large lobe of 

 the distal posterior angle of the 5th segment, which is denticulate on 



187 the posterior margin, and the posterior margin of the 6th segment; the 

 anterior distal angle of the 6th segment is stretched over the claw into 

 a small acute denticle, while the posterior distal angle is produced into 

 a small rounded lobe; the claw is strong and straight. In pereopds II 

 the 5 th and 6th segments are roughly equal to each other while the 

 4th is 2/3 their length; the distal angle of the 6th segment is stretched 

 over and under the claw into straight acute denticles; the claw is strong 

 and straight. Pereopods III and FV have broad distal segments, weakly, 

 denticulate on the posterior margin; the length ratios of the 2nd, 4th, 

 5th, and 6th segments are 18:10:16:13; the claw is small, curved, and 

 retractile. The posterior margin of the 2nd segment of pereopods V bears 

 7 to 11 long denticle-lobes, the anterior margin is armed with sparse 



188 low denticles; the anterior distal angle of the 2nd segment is produced 

 into two long processes, of which the inner is less developed than the 

 outer; the 4th and 6th segments are roughly equal; the 5th segment is 

 slightly longer; the claw is small, curved, and retractile. Pereopods VI 

 are considerably shorter than pereopods V; the length ratios of the 4th, 



