REPORT ON THE CRUSTACEA MACRURA. 179 



extremity of the ophthalraopod when at rest ; the second joint is shorter than the first, 

 and the third is as long as the two preceding put together, and bears at the extremity 

 two long flagella, of which the inner is slender and thread-like, and the outer thicker 

 and gradually increasing in size until near the extremity, when it rapidly decreases 

 to a fine point ; along the thicker portion the flagellum is fringed with membranous cilia. 



The second pair of antennas (c) in our unique specimen has the flagellum broken off at 

 the extremity of the peduncle, which is tolerably robust and nearly as long as that of 

 the first pair. The first or coxal joint articulates freely with the metope, supported 

 on the outer side by a strong tooth ; and supports a prominent and well-defined 

 phymacerite. 



The mandible ((/) is large, having a smooth incisive plate, and a short, strong, three- 

 jointed synaphipod. 



The first pair of siagnopoda (PI. XXIII. fig. le) consists of two single foliaceous 

 plates, fringed on the inner distal margin with a double row of short, closely planted 

 spines and a few short, stiff hairs within, both on the upper and under surfaces ; also a 

 group of longer ciliated hairs on the inner basal margin. The plate is articulated to 

 a short joint, which from analogy I take to be the basis,- on the outer side of which 

 articulates an ecphysis, terminating in a nagelliform lash ending in two long, sweeping 

 hairs. At the base of the branch is a small bundle of cdiated hairs. 



The second pair of siagnopoda (fig. If) consists of three plates, besides the mastigo- 

 branchia; two are foliaceous, divided, and fringed on the inner distal margins with a 

 thickly-set brush of hairs, some of which are stiff and simple, some ciliated, and some 

 curved ; the third plate is narrow and gradually tapers to a point, which turns slightly 

 inwards and terminates in two or three long, simple hairs ; the mastigobranchia is 

 foliaceous, produced anteriorly as far as the extremity of the slender tapering ramus of 

 the same appendage, and is fringed anteriorly with long ciliated hairs that are curved 

 like a hook at the extremity, and posteriorly with a few that are much longer than the 

 rest. 



The third pair of siagnopoda (fig. Ig) has three branches and a mastigobranchia. The 

 inner is foliaceous and fringed on the inner margin with a copious brush of thick hairs, 

 and with a second row evenly arranged behind it on the outer surface : the middle branch 

 is slender and Inarticulate, fringed on the outer margin with a few stiff, simple hairs, 

 and on the inner with others that are long and ciliated : the outer branch is also long 

 and slender, half as long again as the middle ; it is likewise divided into two parts : the 

 basal is fringed on the outer margin with numerous short, ciliated hairs, the inner side 

 is smooth ; the distal division of the branch is multiarticulate, and terminates in a few 

 long, simple hairs ; the mastigobranchia is short, broad, and of extreme tenuity, sparsely 

 protected by a few isolated simple hairs. 



The first pair of gnathopoda (fig. 1//) is subpediform and seven-jointed ; the coxa 



