CRUSTACEA OF THE MERGUI ARCHIPELAGO. 125 
Dimensions of the larger specimen :— 
Breadth of the cephalothorax (distance between 
the second antero-lateral teeth) .......... 23 mm. 
Length of the cephalothorax .............. 15 mm. 
I may here observe that the specimen which Mr. Miers regards 
as Huplax Boscii, Aud. (Zoology of H.M.S. ‘ Alert,’ 1884, p 542), 
is probably some other species. In Huplax Boscit the lower | - 
finger is not at all deflexed, so that it does not make an angle | 
with the lower margin of the palm. Euplax Boscii and MW. de- 
pressus, Ripp., are perfectly distinct species. 
Macrophthalmus depressus has hitherto been recorded only from 
the Red Sea. | 
77. MacroputHaLMus Erato *,n.sp. (Pl. VIII. figs. 12-14.) 
Seven specimens (4 5,3 @) of this small interesting species 
were collected. 
M. Erato belongs to the last section (B) of the genus in Milne- 
Edwards’s Monograph, in which the eye-peduncles do not extend 
beyond the orbits, and in which the cephalothorax is less than 
twice as broad as long. In all the species of this section the 
inner surface of the hands is unarmed, so far as I am aware; in 
this new species it is, however, armed with a short acute spini- 
form tooth, so that I. Erato differs in this character from all 
the species of that section. It is most closely allied, as regards 
its outer appearance, to MM. quadratus, A. M.-E., from New 
Caledonia; but it may be distinguished, according to Prof. A. 
Milne-Edwards, who kindly compared a specimen for me with 
M. quadratus, by the different structure of its orbits, and by 
its comparatively longer, more compressed, and more carinate 
hands. 
The cephalothorax, which is as broad anteriorly as posteriorly, 
is once and a half as broad as long, the distance between the 
second antero-lateral teeth, where the carapace presents its 
greatest width, being, in proportion to the length, as 3:2. The 
regions are distinctly indicated by interregional grooves proper 
to the Macrophthalm:. The cervical suture is deep in its median 
posterior portion, which separates the gastric region from the 
cardiac region, as well as in its lateral branches which define 
the hepatic from the epibranchial region. The grooves 
which separate the protogastric from the hepatic region and 
* Hrato, one of the Nereids. 
