REPORT ON THE CRUSTACEA MACRURA. 601 



margin of the rostrum is deep and laterally compressed, and armed with three teeth, of 

 which the anterior is the largest; between it and the apical tooth the margin is smooth, 

 there being no small teeth, as shown and described in the type specimen. 



The ophthalmopoda (PI. CVIL, a) are pyriform, gradually increasing in diameter from 

 the articulation to the ophthalmus, which is connected with a small, well-defined ocellus 

 at its upper and inner margin, and halfway between the latter and the articulation there 

 is a prominent lobe or tubercle. 



The first pair of antennas (b) has the peduncle shorter than the rostrum, the first 

 joint horizontally depressed and laterally expanded, the outer margin being increased by 

 a wide stylocerite, the point of which reaches nearly to a level with the distal articulation 

 of the second joint. The second joint is armed on the upper and outer angle with a 

 slender sharp tooth ; the third joint is short and carries two very unequal flagella, the 

 upper and outer is short, thick and flattened, about half the length of the peduncle, to 

 which it is attached by a very small pedicle, and suddenly terminates at the apex in a 

 small, slender, and short extremity; the inner flagellum is short, slender, and thread-like, 

 and is subequal with the upper and reaches a little beyond the apex of the rostrum. 



The second pair of antenna? (c) carries a scaphocerite that is subequal with the length 

 of the rostrum ; it is broad at the apex, having the inner margin subparallel with the outer 

 and densely fringed with long ciliated hairs, and the outer strengthened by a ridge that 

 terminates in a subapical tooth. 



The mandibles (d) have the molar process obliquely truncate, and bent at right 

 angles to the apophysis ; the psalistoma is reduced to a small tooth-like process of con- 

 siderable tenuity that terminates in an oblique serrate extremity ; the synaphipod 

 originates close to the base of the psalistoma, and is small, feeble, and two-jointed, the 

 terminal joint being fringed with hairs. 



The first pair of siagnopoda (e) differs from that of Hippolyte in having the outer 

 branch bilobed, and armed on one lobe with a single, sharp, robust spine, and with two on 

 the other. The second pair of siagnopoda has the posterior portion of the large mastigo- 

 branchial plate larger than in Hippolyte, but is otherwise developed in the same form. 

 The third pair (g) as well as the two pairs of gnathopoda (h, i) also resemble those of 

 Hippolyte in form. 



The first pair of pereiopoda (k) is robust, but the propodos is not much broader or 

 longer than the carpos ; it is ovate, and terminates in a chela in which the pollex is more 

 slender than the dactylos. The carpos is about the same length as the propodos ; it is 

 narrower at the meral articulation than at the distal extremity, where the upper angle is 

 cupped and produced slightly over the propodos. The meros is long ; the ischium short 

 and subequal with the basis ; and the coxa carries a rudimentary mastigobranchia (mb), 

 which terminates in a strong hook and is posteriorly fringed with a few simple hairs. 

 The second pair of pereiopoda (I) is slender and chelate ; it has the carpos nearly 



(ZOOL. CHALL. EXP. — PART LII. — 1887.) Fff 76 



