All the legs are fringed with very characteristic hairs of the same 

 kind: they" are long and flexible, and feathered. Many of these hairs, 

 especially on the posterior legs are modified in a most peculiar way: the 

 tip is likewise plumose, but the rest of the hair is transformed into a 

 long, membraneous structure, that is inflated, closed all round and nar- 

 rowing towards the base of the hair. Although gills, si.x in number, are present at 

 either side of the thorax, it may be assumed that the transformed hairs are adopted to oxygen- 

 breathing purposes, and as such hairs are especially numerous on the hinder legs, these should 

 not only prevent the animal from sinking into the soft mud upon which it lives, a supposition 

 made by Alcock '), but also perform the function of gills. Neither in the descriptions, nor in 

 the drawino-s of Alcock, Doflein or Mac Gilchrist did I find similar hairs, so that I believe 

 they are characteri.stic for my species. 



The ambulatory legs are extremely long and slender, the second pair, which is the 

 lono-est, beino- more than 3 times the breadth of the carapace. The meropodites are 5 times 

 as lono- as broad, granular at upper and under surface, serrated and hairy along the borders ; 

 in the case of the .second pair the meropodite is nearly as long as the carpo- and propodite 

 together. The propodite especially is fringed with very long hairs, that are twice or three 

 times as long as the breadth of the joint to which they are inserted; the longest hairs are 

 found at the under or inner border. The dactyli are very long, nearly straight, ending acutely 

 and provided with four sharp ridges (also noted by Doflein in R. chuni)\ the length of the 

 dactyli is variable ; in the first pair of legs they are relatively short, at least shorter than the 

 propodite, and almost naked ; in the second pair they are e.xcessively long, equalling in length 

 the likewise much elongated propodite, and again sparsely hairy ; in the third pair they seem 

 to be as long, but on the left side of the animal this dact\lus is partly broken off, and on the 

 right it is wanting altogether, its outer border is fringed with long hairs. 



The posterior legs are modified in the characteristic way of the genus : they are slender 

 and weak, much shorter than the preceding pairs, reaching somewhat beyond the middle of the 

 length of the meropodite of the preceding legs (in the figure they are represented unfortunately 

 .slightly too long), rising almost on the back of the animal, apparently, in normal position, 

 carried above the plane of the preceding legs and directed straight forward. The last five joints 

 are, however, not equal in length, as stated by Alcock and Doflein, but the carpopodue is 

 distinctly shorter in my specimen. 



The abdomen of the cf occupies all the space between the bases of the posterior legs ; 

 its general shape is triangular, with the 3^ to 6'^ joint of nearly equal length: as in the other 

 species the 3'^— 5"^ joint are fused, but all the segments are distinctly defined by rather deep 

 notches at the margins of the abdomen; the 6'^ segment, as in R. notopus and R. dentata, 

 bears a crescentic ridge near the anterior margin, which ridge projects at either side into a 

 sharp prominence; the terminal segment is longer than the preceding ones and .somewhat 

 longer than broad at the base, with rounded tip (fig. i a). 



l) .\ Naturalist in Indian Seas, Calcutta, 1902, f. 55, opposite p. 252. 



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