216 DE. C. CHILTON ON THE STJBTEEEANEAN 



at the end three or four setae. The carpus is rather longer than the meros, oblong ; the 

 anterior margin with three spiniform setae and two or three simple setae at the end ; the 

 posterior margin straight, with a few simple setae, and in the middle a long " auditory 

 seta." The propodos is similar to the carpus, but considerably longer ; the anterior 

 margin armed with four or five spiniform setae and a few simple ones, the posterior 

 margin having at the extremity a group of two or three simple setae and one " auditory 

 seta." The dactylos is similar to that of the third pair of legs. The spiniform setae on 

 the anterior margins of the carpus and propodos are similar to those on the palms of the 

 second and third pairs of legs, but are smaller and not quite so well marked. 



The fifth and sioctlt, pairs of legs are similar to the fourth, but may sometimes be 

 a little longer. 



The seventh pair of legs is entirely absent in all the specimens that I have 

 examined. 



The first pleopoda (fig. 21) form an operculum completely closing in the branchial 

 plates below. The protopodite appears to consist of two joints, a very short coxa, and a 

 rectangular basos, which is broader than long, and bears on the inner margin three stout 

 setae, dentate at the extremity ; these appear to act like the " coupling-spines " to which 

 Stebbing has drawn special attention in the Amphipoda. The exopodite which forms 

 the operculum is an oval plate bulging downward ; it is about twice as long as broad, its 

 inner margin nearly straight, outer margin very convex, bearing on the distal half about 

 six very delicate plumose setae, with three or four shorter ones at the extremity. The 

 endopodite is narrow styliform, slightly enlarged at the base, somewhat sinuous, sides 

 parallel, extremity rounded and tipped with three or four plumose setae. 



The second, third, fourth, and fifth pleopoda (fig. 22) are all alike and of the usual 

 form. Each consists of a short transverse protopodite, an oval endopodite well rounded 

 at the end and with the margins free from setae, and a longer and rather narrower 

 expedite, which is slightly constricted on the outer margin toward the extremity ; the 

 margin is rather irregular, and bears a few finely plumose setae on the inner side and at 

 the end, with sometimes one on the outer side. The number of these setae appears to 

 vary somewhat in the different pleopoda, but I have not noticed any other differences 

 between them. 



I have not hitherto met with any special modification of the pleopoda of the male 

 like that occurring in the Asellidae, «JcC., and do not know whether such a peculiarity 

 has been recorded in the Anthuridae. 



The tiropoda (fig. 23) are articulated to the end of the sixth segment of the pleou. 

 The basal portion or peduncle is large, flat, and nearly rectangular, and reaches nearly to 

 the end of the telson ; it is about two and a half times as long as broad ; the outer margin 

 is straight and bears a few setae on the distal half; the inner portion extends as a flat plate 

 to the median line of the body, the right or the left uropods often having then- inner 

 margins in contact below the telson ; the inner distal angle bears a single small seta. 

 The endopodite is articulated to the posterior margin of the peduncle on its outer half; it 

 is oblong, more than three times as long as broad, extremity rounded, the end and the two 

 margins being fringed with long setae, which are thickest and longest at the extremity ; 



