Chilton. — Ceina, an Aberrant Genus of the Talitridae. 



121 



alternate bands of purplish pink and white."* Tliis specimen was found 

 among corallines, and the general appearance of the animal caiised by its 

 dorsal crest, the way in which it coiled itself up, and by its colour, was very 

 suggestive of a piece of coralline. 



The peraeon and pleon are strongly compressed dorsally and carinate, 

 the first segment of the peraeon forming a rounded crest projecting forwards 

 over the posterior part of the head. Comparison of a number of specimens 

 shows that the amount of carination is approximately the same in both 

 sexes, though in the original description it was stated that the female 

 was more strongly carinated than the male. The carination is naturally 

 less marked in immature specimens. 



The upper surface of the head is turned slightly upwards at the base 

 of the upper antenna. 



Fig. 2. — Ceina egregia ; dorsal view of female. 



The eyes are round and of moderate size, containing numerous ocelli ; 

 they are red in colour, and project a little beyond the surface of the head 

 as a small convex lobe on each side. 



The various appendages may be described as follows : — 



The upper antenna (fig. 3) is rather longer than the peduncle of the 

 lower ; the first joint of the peduncle is longer than the second, and is 

 produced at the lower distal angle into a subacute tooth ; the third joint 

 is slightly shorter than the second. The fiagellum is as long as the peduncle, 

 and consists of about 9 joints, all of which bear numerous simple 

 ■' olfactory " setae in addition to a few ordinary acute setiiles. In one 

 ovigerous female examined the flagellum contained only 7 joints. 



The second antenna (fig. 4) has the last joint of the peduncle rather 

 longer than the penultimate ; the flagellum is rather stout, longer than 

 the peduncle, and containing about 13 segments, each with tufts of short 



* Tliis banding of the antennae with different colours is very common in the 

 Amphipoda, and its effect is to disguise the length of the antennae as the animal lies 

 against seaweed, rock, &c., and thus render it less conspicuous. 



