REPORT ON THE BRACHYURA. 
203 
the sides slightly arcuated, and it is strongly excavated at its distal extremity, where it 
receives the very small transverse terminal segment, which is distally rounded. The 
eyes are large and thick, and their cornese occupy a large part of the inferior surface of 
the peduncle. The antennules are long, with the basal joints considerably enlarged, and 
they terminate in two short flagella. The short oblong basal joints of the antennae 
occupy the w T hole of the space between the inner subocular spine and the basal joints of 
the antennules ; the second and third joints are slender and short, the flagella (in the 
male) rather long, composed of upwards of thirty joints. The outer maxillipedes have 
the ischium (as in Platyonychus ocellcitus ) longitudinally canaliculated ; the merus is 
longer than broad, obliquely truncated at its distal extremity, with the antero-external 
angle rounded, the antero-internal angle not (as in Platyonychus ocellcitus ) greatly pro- 
duced, but terminating in a small rounded lobe as in Platyonychus hipustulatus. The 
chelipecles (in the adult) are robust and elongated ; the merus-joint is armed with three 
to five spinules on the distal half of its anterior margin ; the carpus is granulated above, 
and is armed with three spines (one on its inner surface, one on its outer, and one, distal, 
above the articulation with the wrist); the palm is about as long as the merus, longitudin- 
ally concave, and very coarsely granulated, on its upper surface more finely granulated, 
with two longitudinal ridges on the outer surface, and with four or five spinules on 
the distal half of its upper and inner margin ; the fingers are longer than the palm ; the 
dactyl has five or six strong spines on its upper margin, both fingers are incurved at the 
tips, and strongly dentated on their inner margins, the teeth disposed nearly as in 
Platyonychus hipustulatus. The second to fourth legs are compressed, nearly smooth, 
with the dactyli slenderer and more elongated than in Platyonychus ocellatus and Platy- 
onychus hipustulatus ; the fifth legs are nearly as in Platyonychus ocellatus, with the 
antepenultimate joint carinated above, the penultimate and terminal joints greatly 
compressed, the terminal joint large and ovate. Colour (in spirit) yellowish-brown; the 
legs, and especially the chelipedes, are strongly and beautifully iridescent (hence the 
specific name). 
The largest male and female have the following dimensions : — 
Adult ?. 
Lines. 
Millims. 
Length of carapace and rostrum, 
23 
48-5 
Breadth of carapace, .... 
28 
59-5 
Length of a chelipede, nearly 
43 
91 
Length of first ambulatory leg, 
36 
76-5 
Length of fifth ambulatory leg, 
29f 
61 
Adult $ . 
Length of carapace and rostrum, about 
18 
38-5 
Breadth of carapace, .... 
211 
45 
Length of a chelipede, about 
35 
74 
Length of first ambulatory leg, 
30 
63-5 
Length of fifth ambulatory leg, 
27 
56-5 
