506 THE VOYAGE OF H.M.S. CHALLENGER. 



and basis, articulate with each other, the latter bears a small ecphysis, and the suc- 

 ceeding two, the ischium and meros, are closely impacted or fused together, and can be 

 defined by their line of demarcation rather than by their articulation ; the carpos is fused 

 either with the meros or propodos, which latter is broad and articulates with the 

 preceding joint obliquely downwards, and is distally united with the dactylos, which is 

 as wide at its base as the propodos ; it is fringed with short, strong, rigid spinules, and 

 terminates in a long, stiff, smooth, and sharp pointed unguis. 



The first pair of pereiopoda is a stout and powerful appendage ; the coxa and basis are 

 short and articulate freely ; the ischium is fused with the meros, but is short and clearly 

 defined ; it projects on the inner surface to a large tooth, while the meros is long and 

 subcylindrical ; the carpos is short but broader distally than at the meral articulation ; 

 the propodos is long and ovate, and articulates with a strong and simple dactylos. 



The second pair of pereiopoda is long and slender ; the coxa and basis are short, the 

 ischium is long, broad, and flat, being longitudinally concavo-convex ; the meros is long, 

 narrow and cylindrical ; the carpos is long and multiarticulate ; the propodos is short 

 and with a minute dactylos forms a small but perfect chela. The two sides are uniform. 



The two following pairs are similar to each other, being long, slender, and cylindrical, 

 and terminate in long, slender, and styliform dactyli. The posterior pair is liable to 

 vary specifically in form. 



The first pair of pleopoda is unequally biramose, differing in the male from that in 

 the female in being larger and more robust ; the inner branch supports a stunted 

 stylamblys tipped with numerous cincinnuli, while that of the female is narrow and 

 foliaceous. The second pair is alike in both sexes, differing only in the male having 

 two stylamblydes attached to the inner ramus, while there is only one in the female, the 

 ova being attached to the hairs, not of the branches, but of the basal joints only. The 

 other pleopoda resemble the preceding, increasing in size posteriorly to the fourth, the 

 fifth pair being smaller, while the sixth forms the outer plates of the rhipidura, and are 

 broad and foliaceous, rounded at the extremity and shorter than the telson. 



The branchiae (PI. XCIII. fig. 1) consist of six large pleurobranchial plumes, of which 

 the posterior is the largest, and four arthrobranchise, and may be best understood by the 

 following table : — 



Pleurobranchise, . . ... 1 1 1 1 1 1 



Arthrobranchiffi, . . . ... 1 1 1 1 



Podobrancliife, ... 



Mastift'obranchias, . . . 



Development. — I have not found any specimens of the young at any stage, but one of 

 the females of Glyphocrangon granulosis, from the north of New Guinea, had numerous 

 large ovate ova that were nearly ripe for extrusion, so that by extracting the embryo 



