Calamorhynchus. 73 



in his Report on the »Challenger» Amphipoda. The two species are 

 distinguished from one another by the length of the seventh pair of 

 perœopoda, and by that of the uropoda. 



A. The seventh pair of perîeopoda are scarcely longer 



than the femur of the sixth. 1. C. pellncidus. 



B. The seventh pair of peraeopoda are nearly as long as 



the whole sixth pair. 2. C. rigidus. 



1. CalamOliiyilcllUS pelllicidus, Th. Streets, 1878. 



PI. II, fig. 14 and 15. 



Diagn. The head is much longer than the whole perseon ; the rostrum 

 is shorter than the ocular region of the head. 

 The second pair of perœopoda are nearly cheliform, with the 

 front margin of the carpal process as long as the hind 

 margin of the metacarpus. The femur of the last three 

 pairs is lanceolate ; the seventh pair are scarcely longer 

 than the femur of the sixth pair. 

 The first pair of uropoda reach to the apex of the second, 

 but de not attain the apex of the last pair, which are a 

 little shorter than the telson. 



Syn. 1878. Calamorhynchus pellncidus, Th. Streets. 26, p. 285, pi. 2, fig. 5. 



From the original description of Streets I add the following 

 details: 



»Head long, nearly one-third of the total length, its breadth twice 

 that of the thorax; neck short, and slightly narrower than the thorax; 

 the portion containing the eyes oblong, convex above and below when 

 viewed in profile, elevated above, in the median line, into a sharp ridge, 

 which terminates at the apex of the rostrum, below the eyes form two 

 long and rounded lobes separated by a hroad, shallow groove; rostrum 

 flattened, posteriorly broader than the eyes, commencing an either side 

 of the eyes in a broad, rounded wing-like expansion, and tapering forward 

 to a long and acute apex. — — — Segments of the thorax subequaL 

 — — — The anterior three abdominal segments subequal, the postero- 



Nova Acta Reg. Soc. Sc. Dps. Ser. III. 10 



