REPORT ON THE CRUSTACEA MACRURA. 61 



is foliaceous, narrow, with parallel straight sides, terminating in a rounded extremity 

 fringed with spines. 



The gnathopoda are short, peculiar, hut not abnormal. The first pair lias the dactylos 

 broad and spatuliform, fringed with a series of deeply-implanted stiff spines ; the propodos 

 is broad, short, and flat, as is the carpos, which has the outer margin long and curved, the 

 inner short, and consequently, in articulating at one extremity with the meros, and at the 

 other with the propodos, induces a sudden and permanent curve ; the meros is broad, and 

 longer than either of the other joints, fringed on the inner side with long hairs ; ischium 

 short and broad, and fused with the basis, which carries a tolerably long ecphysis, ter- 

 minating in a multiarticulate lash, fringed with hairs ; coxa short, and supporting a broad 

 mastigobranchia, with a narrow rigid neck, on the anterior side of which is a short and 

 rather small podobranchia, whfle at the membranous pleural articulation two arthro- 

 branehia3 are attached, the anterior being small, not larger than the podobranchia, and the 

 posterior is much larger and longer. 



The second pair of gnathopoda has the dactylos long and slender, diagonally flat- 

 tened, and fringed with spines : the propodos is not longer than the dactylos, rounded 

 on the outer side-, and flattened on the side nearest the mouth; the carpos is short, 

 curved, and arched, articulating with the meros on the under side (or that nearest the 

 mouth) ; the meros is longer than either of the other joints, having the distal extremity 

 produced into a large, smooth lobe that projects beyond the carpos ; inner margin 

 flattened, against which the reflexed distal joint presses ; upper surface engrailed at the 

 inner margin ; outer margin flattened to a thin serrate crest : the ischium is broad and 

 flattened to a thin, smooth crest on the outer margin, thickened on the inner side to a 

 double margin, the upper of which is smooth, the lower evenly denticulated, the inter- 

 mediate space being hollow and smooth : the basis is short and narrow, attached to if 

 not actually anchylosed with the ischium, which is thickened on the inner side, where 

 the distal angle is produced to a broad obtuse point, while the outer is flattened and 

 shortened to a process that supports a rigid two-jointed ecphysis, the basal joint of 

 which is serrate on the outer surface, and multi-articulate and hairy on the distal : the 

 coxa is broad and flat on the outer surface, and produced to an obtuse tooth or point 

 on the inner anterior angle. It supports a broad, bat-shaped mastigobranchia projected 

 on a slender stalk, to which is attached a podobranchia about half its length ; and to 

 the podopleural articulation are attached two, not very large arthrobranchias. 



The first pair of pereiopoda is acuminate, and but slightly more robust than the 

 succeeding pairs, even in the male. It carries a pointed bat-shaped mastigobranchia, 

 supported on a slender stem, to the base of which is attached a podobranchia about the 

 same length as itself ; to the podopleural articulation are attached two arthrobranchise, 

 of which the anterior is the smaller, and lies over the posterior. The three succeed- 

 incr pairs of pereiopoda have the branchial plumes larger than the first, and have 



