REPORT ON THE CRUSTACEA MACRURA. 869 



that is attached by a small pedicular articulation ; the ischium is short and about half the 

 length of the ecphysis ; the meros is long and slender, the carpos short and narrow, and 

 the propodos long, slender, and tapering, the extremity being broken off in our specimen; 

 the dactylos, which is probably minute, is missing. The fourth pair of pereiopoda (w) is 

 much shorter than the third, and differs from it in having the propodos cylindrical and 

 not tapering, being as broad at the distal as at the meral extremity ; the dactylos is short, 

 broad, and flat, and tipped with hairs. 



The fifth or posterior pair of pereiopoda (0) is considerably longer than the fourth and 

 stouter than the third ; it is formed as in the preceding, but differs in the shape of the 

 dactylos, which is flattened and increases in diameter distally, where it terminates in a 

 rounded extremity ; the distal and inner margin being fringed with long and short hairs 

 respectively. 



The branchiae (PI. CXL. fig. 2) of this species are peculiar, but from the small number 

 and size of the specimens I have not had the opportunity to determine if the condition 

 be generic or not. There are none corresponding with the gnathopoda, while those that 

 belong to the first two pairs of pereiopoda are attached to the membranous portion of 

 the coxa] articulation, and are of equal size and importance ; those of the third pair are 

 unequal, and those of the posterior two pairs are attached to the interstitial portion of 

 the somites of the pereion and therefore are pleurobranchise, while the former are 

 arthrobranchias as shown in the table given under the genus. 



The pleopoda are biramose and multiarticulate. The first pair (p) has the outer 

 ramus long, slender, and fringed with ciliated hairs ; the inner ramus is short, flat, and 

 membranous, of great tenuity, and fringed with short, strong, ciliated hairs on the 

 posterior and distal surfaces respectively, and on the anterior margin there is a pointed 

 process that I take to be the rudiment of a stylamblys. The second (q) and all the 

 following pairs have the branches subequal in length, the inner, which carries a long, 

 cylindrical, narrow stylamblys, tipped with cincinnuli, being narrower than the outer. 

 The terminal pair, which helps to form the rhipidura, has the outer branch much 

 longer than the inner, and is traversed by a diaeresis (v) that is imperfectly defined 

 on the outer margin, and does not reach the inner, which like both margins of the 

 inner branches is fringed with strong and ciliated hairs. 



In our specimen, which I consider to be a female, there is a mass of parasitic cell- 

 growth (fig. 3) strung together in a bead-like arrangement and suspended from a common 

 centre. On casual inspection the appearance as seen through the thin structure of the 

 integument is that of a mass of ova peculiarly arranged, but closer and more careful 

 examination demonstrates the parasitical nature of the growth. 



The specimen was associated with one of Sergestes, so much like it in general 

 appearance, although smaller, that it might easily have been taken for a younger 

 specimen. 



