8 SLADEN TRUST EXPEDITIONS TO ABKOLHOS ISLANDS. 
tooth near the base of the nail. The whole limb recalls to some extent that 
found among the males of the genus Elasmopus, though it is not setose at 
all. Stebbiug, in the 'Challenger' Report and in recording this species 
from South Africa, notes the dissimilarity between the right and left second 
giiathopods in some of his specimens ; but the dissimilarity usually takes the 
form of one of the gnathopods being of the female type and the other of 
the male. No such striking instance as the present one has been noticed 
before. 
With regard to the serrations on the epimeral phdes of the first three 
segments of the pleon, the t3'pical form has one or two serrations on the 
lower margin in all three segments, bat only the third segment is serrated on 
the hind margin. Clhevreux describes serrations on both lower and hinder 
margins of the epimeral plates of the second and third pleon segments in 
specimens from French Oceania. Haswell says of Australian specimens 
" lateral plates (epimera) of the three anterior segments of the pleon 
serrated posteriorly,'" while in Mara spinosa, now regarded as a synonym of 
C. rubromaculata, he gives only the third segment with serrations on the 
posterior margin of the lateral plate. There is thus abundant evidence of 
variation in this character. I may note that, in all my specimens, the first 
joint of the mandibular palp has a spiniform process on its inner corner as 
described by Walker (1904) and CJhevreux (1907). 
Genus M^EKA, Leach. 
5. M^KA TENELLA {Dana). 
Gmnviarus tenelhis, Dana, 1853, p. 952, pi. 65. fig. 7. 
Mcera tenella, Walker, 1904, p. 272, pi. 5. tig. 31. 
M. tenella, Stetbiiig, ISOG, p. 438. 
Locality. Wooded Island, Easter Group, one male, 5 mm. 
Remarks. The single specimen agrees closely with the description and 
figures of a specimen from Ceylon referred to Dana's species by Walker. 
The only noteworthy point of difference is that the dactylus of the second 
gnathopods in the male has a well-marked tooth about the centre of its inner 
margin, which fits into a corresponding excavation on the palm. The serrate 
hind margin of the third segment of the pleon and the slightlj^ different 
form of the second gnathopods of the male seem to distinguish this species 
from M. viridis, Haswell, to which it is otherwise very closed allied : in fact, 
this species seems to me to afford an additional argument in support of 
Chilton's contention that Haswell's species belongs to the genus Ma'ra, and 
not to Elasmopus to which Stebbing would refer it. 
Distribution. Fiji (Dana) ; Ceylon (Walker). 
