Braclnjxtran Genera Miclppoides and Ilyustenus. 313 



upper orbital marj^iu as projecting iu a well-marked corner 

 anteriorly and the basal segment of the antenna as hardly 

 hmgcr than broad. In all the specimens I have seen the 

 anterior corner of the upper orbital margin is practically 

 obliterated. In the old Fiji and Australian specimens the 

 basal antennal segment is nearly as broad as long, with the 

 outer margin expanded into a semicircular lobe which forms 

 a distinct tloor to the orbit and is separated by a rather 

 narrow gap from the postorbital process. In the Christmas 

 Island specimens, as shown in the figure given iu my former 

 paper, the basal segment is not more than three-fourths as 

 broad as long, its outer margin is only slightly convex, and 

 the gap between it and the postorbital process is widely open. 

 The result of all this is that the orbits — which in Milne- 

 Edwards's figures look so tubular as to lead Alcock (Journ. 

 Asiatic Soe. Beufral, Ixiv. pt. 2, pp. 1G7 & 255) to place the 

 genus in his alliance Periceroida, and to suggest that it 

 might " w ithout any unnatural stretch " include Macrocaloma 

 and Entomomjx — are not only, as Miss Rathbuu notes, 

 " much less tubular than in Macrocoeloma,'' but are even, in 

 tiie Ciiristmas Island specimens, less completely enclosed 

 than in some species of Hyasteniis. There can be little 

 doubt that JNIiers was right when he placed the genus in the 

 vicinity of Hyastoins and Nuxia, and even the resemblance 

 which he admits to the Periceroid Prionorhynchus is, perhaps, 

 not more than superficial. 



The only other species that I find referred to the genus 

 Micippoides is M. longimanus, Haswell (Proc. Linn. Soe. 

 N. S. W. iv. p. 444, pi. xxvi. fig. 5, 1879), of which I have 

 examined a specimen. It is hardly possible to regard this 

 species as congeneric with M. angustifrons, from which it 

 diflers considerably in the structure of the orbital region, 

 but I am not prepared to suggest its proper place in the 

 classification. 



Genus IIyastenus, White. 



Hyasfenus, White, Proc. Zool. Soe. 1847, p. 66, 



" JIalimus, Latreille," Rathbun, Pioc. Biol. Soe. Washington, xi. p. 157 



(1897) ; nee Huliiims, Latreille, Kegne Animal, nouv. ed. iv. p. 60 



(1829). 



The name Hyastemis, proposed by White in 1847, was 

 used for half a century, without any ambiguity or incon- 

 venience, to denote a well-known genus of Indo-Pacific 

 Brachyura, In 1897, however, jNIiss Rath])uu proposed to 

 transfer to this genus the name Halimvs, which had been 

 employed till then for an entirely different genus from 



