REPORT ON THE CRUSTACEA MA CRURA. 107 



neither does the basis, which is short, and closely associated with the rneros, and has the 

 inner margin fringed with four or five cusp-like teeth ; the ischium is short, and armed 

 with two short cusps on the inner margin; the meros is long, ovate; the carpos is curved 

 and triangular ; the propodos is narrower than the carpos, cylindrical, and continuous 

 with the dactylos, but defined from it by a strong spine on the upper and one on the 

 lower margin ; the dactylos is sharp-pointed. 



The second pair of gnathopoda (i) — represented relatively too small in the figure — is 

 long and slender, being twice the length of the first pair. The coxa is broad, fringed 

 along the upper margins with long ciliated hairs, and carries a slender mastigobranchia, 

 fringed with ciliated hail's near the base, and throughout the rest of the surface with 

 hairs in which the cilia are differentiated into small points; the basis is short, 

 armed with three small cusps, and fringed with long ciliated hairs ; the ischium is 

 ovate, long, flat, and covered with long hairs fringed with cilia, which are longer 

 on the posterior than on the anterior surface ; the meros is long, ovate, but shorter 

 than the ischium, and not quite so broad ; the carpos is shorter and narrower than 

 the meros ; the propodos is rather shorter than the carpos, and cylindrical ; the dactylos 

 is as long as the propodos, and terminates in a styliform unguis, supported by a secondary 

 one on the lower or concave margin. There is no branchial plume connected with this 

 pair of appendages. 



The first pair of pereiopoda (k) is long and slender, being about once and a half as long 

 as the animal measuring from the rostrum to the extremity of the telson ; the coxa is 

 broad, and supports an ecphysis in the form of a mastigobranchial plate on a long stalk, 

 and a short podobranchial plume attached to its outer or posterior margin ; the basis is 

 short, and carries no ecphysis, it articulates with the coxa, which is attached to the 

 ischium; the ischium is long, slender, flattened and curved, gradually increasing in width 

 as it proceeds from the basisal joint ; the meros is flat and very long, being three times 

 the length of the ischium, from the extremity of which it gradually widens, and then 

 more gradually narrows to comparative tenuity ; continuing so for some distance, it 

 again gradually enlarges a little at the carpal extremity, where it is armed on the outer 

 angle with two curved unecpial teeth ; the inner margin is straight and fringed with 

 numerous small denticles, every third one of which is larger than the intermediate ones ; 

 the outer margin is wavy and smooth ; the carpos is long and slender, very nearly as long 

 as the meros, the margins are parallel from one extremity to the other, the inner is smooth 

 but the outer is fringed with a few denticles and has its distal angle, where it widens for 

 the purpose of articulation, furnished with a moderately strong tooth. There is a slight 

 curve near the meros, which must prevent the appendage from being extended in a straight 

 line ; the propodos is long, and including the pollex, longer than the carpos ; its sides 

 are parallel, and the pollex is continuous with the inner margin of the palm, and armed 

 with one straight, perpendicular tooth (k") on the inner surface one-fourth from the 



