CETTSTACEA 01" THE MERGTJI AECHIPELAGO. 12 5 



Dimensions of the larger specimen : — 



Breadtliof the cephalothoras (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 Euplax Boscii, And. (Zoology of H.M.S. ' Alert,' 1884, p 542), 

 is probably some other species. In JEuplax Boscii 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 M. de- 

 pressus, E-iipp., are perfectly distinct species. 



Macrophthalmus depressus has hitherto been recorded only from 

 the Red Sea. 



77. Macrophthalmus Eeato *, n. sp. (PI. YIII. figs. 12-14.) 



Seven specimens (4 J , 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 o£ 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 M. Erato differs in this character from all 

 the species of that section. It is most closely allied, as regards 

 its outer appearance, to M. 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 

 Jf. q^uadratus, 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 MacropMhalmi. 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 

 * Erato, one of the Nereids. 



