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



of Diogenes varians, in having the left chelipede with a tendency towards spinulation 

 on its joints, and the lower border of the propodus curved ; the ophthalmic scales also 

 are sparingly dentate. 



Diogenes guttatus, n. sp. (PI. VI. fig. 4). 



Character's. — The anterior portion of the carapace is slightly convex from side to 

 side and smooth towards the centre ; the front with its median process faintly marked, 

 but a conspicuous projection external to each ophthalmic scale ; the antero-lateral 

 border (posterior to the insertion of the antennal peduncle) with an abrupt slope 

 backwards, and armed with a few minute spinules ; the lateral margin with about 

 six acute curved spinules. The central portion of the carapace behind the cervical 

 groove has a few granulations. 



The rostriform process is entire, narrowing towards the acute apex which scarcely 

 reaches the end of the o^^hthalmic scales ; the latter are subentire, with two or three 

 spinules at the inner and distal margin. The ocular peduncles extend to a point opposite 

 the middle of the terminal joint of the antennal peduncle and the commencement of the 

 same joint in the antennular peduncle. The antennal acicle is short, not reaching beyond 

 the middle of the penultimate joint of the peduncle, and its inner border is quadrispinose ; 

 the second joint of the peduncle is broad, and possesses a prominent external spine ; 

 the flagellum is not twice the length of the carapace, and its under surface is fringed 

 with long hairs. 



The left chelipede has the meral and carpal joints subequal, slightly pubescent, and 

 covered with spinuliform granulations, most strongly marked towards the borders, on 

 which they become distinctly spinulous ; the inner surface of the carpus is convex ; the 

 propodus is about one and a half times the length of the carpus, its outer surface is covered 

 with perfectly circular, drop-like, and flattened elevations, the ujDjjer and lower borders are 

 spinulous and almost straight ; on the outer surface and near the carpal articulation are 

 three curved denticles situated near the lower border, the inner surface is faintly 

 granular ; the dactylus has a series of dentations on the upj^er border and numerous 

 granulations on the outer surface, the lower border is minutely toothed; the immobile 

 finger has an obscure median ridge on the upper surface and numerous small teeth on the 

 inner margin. The right chelipede is wanting in the single specimen. The first and 

 second pairs of ambulatory limbs are smooth and sparingly ciliated, with a few spinules 

 on the anterior borders of the meral joints ; the dactyh are slightly bent, longitudinally 

 canaliculate on the upper surface, and considerably longer than the propodi. The pen- 

 ultimate joint of the fourth leg has its lower border spinose. 



The two terminal segments of the abdomen are smooth and moderately convex, the 

 ultimate is longitudinally channelled. 



