202 
THE VOYAGE OF H.M.S. CHALLENGER. 
Platyonychus ocellatus (Herbst). East Coast of United States ; Gulf of Mexico, 
New Zealand (Dr. J. Hector). 1 
Platyonychus hipustulatus, Milne Edwards ( = Anisopus punctatus, de Haan ; 
Portunus catharus, White ; Platyonychus purpureus, Dana). Indo- 
Malaysian, and Australian Seas; New Zealand; Chili; West Patagonia, 
Trinidad Channel. 
Platyonychus iridescens, n. sp. Ki Islands, 140 fathoms (Station 192). 
Platyonychus hipustulatus, Milne Edwards. 
Platyonychus hipustulatus, Milne Edwards, Hist. Nat. Crust., vol. i. p. 437, pi. xvii. figs. 7-10, 
1834. 
„ „ A. Milne Edwards, Archiv. Mus. Hist. Nat., vol. x. p. 413, 1861, 
and references to synonyms. 
Corystes (Anisopus) punctatus, de Haan, Crust, in v. Siebold, Fauna Japonica, pp. 13, 44, pL ii. 
fig. 1, 1835. 
Off the South Australian Coast, 2 to 10 fathoms, April 1874. 
(two males and a female). 
Adult S ■ 
Length of carapace, ....... 
Breadth of carapace to base of lateral epibranchial tooth, 
Three small specimens 
Lines. Millims. 
20 
11 23-5 
Platyonychus iridescens, n. sp. (Pl. XVII. fig. 2). 
The carapace in this fine species is shaped nearly as in Platyonychus ocellatus and 
Platyonychus hipustulatus; it is moderately convex, broader than long, with the antero- 
lateral margins arcuated and shorter than the concave postero-lateral margins ; its surface 
is rather coarsely granulated, except near the front, and in the posterior parts, near the 
posterior margin, the shallow depressions indicating the cervical suture are as distinct as 
in Platyonychus ocellatus. The front (as in that species) is armed with three spines 
(the lateral spines being those of the inner angle of the orbit), the median spine, although 
somewhat more prominent than the lateral spines, is not nearly so large as in Platyonychus 
ocellatus. The orbits have a notch in their upper margins, and a spine at the inner 
subocular angle. The antero-lateral margins are armed with five rather distant spiniform 
teeth ; the first (or exterior orbital tooth) is rather prominent, the second and third smaller 
and rather more closely approximated than are the other antero-lateral teeth. The 
pterygostomian regions are granulated, and are marked (as in Platyonychus ocellatus) 
with an oblique granulated line extending to the antero-lateral angles of the buccal 
cavity. The segments of the post-abdomen are distinct, in the male the first and second 
segments are small, the third transversely carinated ; the sixth segment is longest, with 
1 Trans. New Zeal. Inst., vol. ix. p. 473, pl. xxviii. fig. 1, 1877. 
