f 
186 THE VOYAGE OF H.M.S. CHALLENGER. 
From the European and East American genus Bathynectes, Stimpson , 1 with which 
Thranites, Bovallius, is I think, synonymous , 2 this genus is distinguished by the more 
elongated and less squarely truncated apex of the merus of the exterior maxillipedes, and 
by the more dilated and ovate dactylus of the fifth ambulatory legs. 
Besides the Australian and Malayasian Lupocyclus rotundatus , Adams and White, 
the only species referable, as far as I know, to this genus is the Lupocyclus philip- 
pinensis, Nauck, and the one described below, which differs from the type and approaches 
Bathynectes in the more elongated and lateral epibranchial tooth of the carapace, and 
the short chelipedes, on which account I refer it to a new subgenus. 
Lupocyclus (Parathr unites) orientalis, n. sp. (PL XVII. fig. l). 
The carapace is hexagonal, broader than long ; its upper surface is rather coarsely 
granulated and tuberculatecl ; the tubercles disposed as follows : — one on the gastric and 
two on the cardiac region, and on either side of the gastric and cardiac tubercles usually 
three smaller prominences, in a longitudinal series ; the front is rather narrow (as in 
Lupocyclus rotundatus ), and has four small spinuliform teeth, the two median of which, 
in the adult, are usually more prominent than the lateral teeth, which are at the inner 
angle of the orbit. The antero-lateral margins are arcuated and divided into five teeth, 
the first four of which are broad and equidistant (shaped much as in Platyonychus 
bipustulatus), the last is spiniform and laterally porrected ; the concave postero-lateral 
margins terminate in a small spinule at the postero-lateral angles of the carapace; the 
upper margins of the orbits are divided by two narrow fissures (as in Lupocyclus 
rotundatus), the inferior margin is emarginate below the tooth at the exterior orbital 
angle. The pterygostomian regions are granulated. The narrow transverse epistoma is 
shaped nearly as in Lupocyclus rotundatus. The terminal segment of the post-abdomen 
is longer than broad, and narrower at its base than the penultimate segment. The eyes 
are rather small. The basal joints of the antennules are broadly dilated, as in 
Lupocyclus rotundatus, and are distally truncated or slightly concave. The slender and 
narrow basal joint of the antennae is not in contact with the basal antennulary joint or 
with the margin of the wide orbital hiatus, and does not attain the apex of the inner 
subocular lobe of the orbit ; the two following joints are slender and rather short, the 
flagellum moderately elongated. The outer maxillipedes are granulated on their exterior 
surface ; the ischium is elongated and longitudinally sulcated, the merus narrowed to 
its distal extremity, which is rounded ; the narrow and straight exognath reaches the 
distal extremity of the merus-joint. The chelipedes are of moderate size ; the trigonous 
merus-joint is armed commonly with a single spine on its anterior margin, and two on 
1 Bull. Mus. Comp. Zodl., vol. ii. p. 145, 1870. 
2 Ofversigt k. Vetensk.-Akad. Forhandl., vol. xxxiii. No. 9, p. 59, pis. xiv., xv., 1876 ; op. cit., vol. xxxviii. No. 2, p. 9, 
pi. ii., 1881. 
