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



fifth, a row of four rather long spines on its front margin, each between two short ones ; 

 the fifth with five sets of spines on the front, each consisting of a long and a short spine, 

 except the lowest set, in which the spines are equal. The finger is long and slender, 

 curved near to the small nail. 



Fifth Perxopods. — First joint broader and longer than that of the preceding pair, 

 widest above ; third joint not dUated ; rest of limb missing. The branchial vesicles were 

 not in a good state for observation ; they presented many irregular folds, and the usual 

 gradations of size. 



Pleopods. — So far as examined these correspond very nearly with those described for 

 Hippomedon geelongi. Six cleft spines were observed on one of the rami. 



Uro2Jods. — Peduncles of the first pair longer than the rami, outer ramus rather longer 

 than the inner, small spines on the upper margins, four on the outer ramus, three on the 

 inner, a short bright nail at the tip ; in the new rami in a state of preparation within 

 the old this bright nail makes itself conspicuous, as though it were already a part of 

 the outward armature (see fig. i(,r.2.). Peduncles of the second pair shorter than 

 the rami, which are similar to those of the first pair, except that they are shorter 

 without being less broad ; peduncles and rami of the third pair shorter than those of the 

 second pair, though not greatly so ; outer ramus longer than inner, with some small spines 

 along the side ; each ramus ends in a small nail to which it rather abruptly narrows, 

 and each has the border fringed with very long plumose setse. 



Telson. — Much longer than broad, cleft about four-fifths of its length, distally narrowing 

 a little, but so as to leave both divisions broad-ended. In a small emargination at the 

 outer part of each apical border is a stout spine with a cilium close on each side of it. 

 The inner part of the apical border is rounded. On each side nearly on a level with the 

 top of the cleft is a feathered cilium, and two spines on the margin lower down. 

 Length. — The specimen, without the antennae, was nearly half an inch long. 

 Zocfliii;?/.— Station 162, ofi" East Moncoeur Island, April 2, 1874 ; lat. 39° 10' 30" S., 

 long. 146° 37' 0" E.; depth, 38 fathoms; bottom, sand and shells. One specimen. 

 Dredged, 



Remarks. — There is much agreement between this species and Hippomedon her- 

 gueleni, Miers. To call attention to this, and at the same time to show respect to the 

 clever naturalist who first described the species just mentioned, I have named the present 

 species Hippomedon miersi. It possesses that character of the antennae which Boeck 

 makes generic, but which is perhaps peculiar to the male. It has many sufficiently distinct 

 features, in the first joint of the flagellum of the upper antennae, the long third joint of 

 the mandible palp, the first side-plate of the peraeon, the third pleon-segment, the tips 

 of the uropods, the broad termination of the telson, and other details. 



