162 — DR. J. G. DE MAN ON THE PODOPHTHALMOUS 
88. Merrapiax pentTIPEs, Heller. (Pl. XI. figs. 1-3.) 
Helice dentipes, Heller, Crustaceen der Novara-Reise, p. 62, Taf. v. 
fig. 5. “. 
Helice dentipes, Kingsley, Carcinological Notes, no. iv. Synopsis of 
the Grapside, Proc. Acad. Nat. Sci. Philadelphia, 1880, p. 229. 
This species is represented by a fine series of thirteen speci- 
mens of various sizes, viz.: one adult male specimen, found at 
Tavoy, two young individuals from the Rangoon river, two 
younger individuals from a mangrove-swamp at Zediwon, and 
eight other specimens from the same locality. 
This species has hitherto been very unsatisfactorily known, as 
only a young female specimen was described by Heller; the 
interesting characters of the male were unknown. The Mergui 
specimens, however, undoubtedly belong to MHeller’s Helice 
dentipes, which may be easily distinguished from the allied species 
by the less enlarged cephalothorax, by the structure of the infra- 
orbital ridge, and by some other characters. 
This species is closelv allied to Metaplax distinctus, M.-Edw., 
the upper surface of the cephalothorax in both species being 
almost similar, but the cephalothorax of I. dentipes is not 
so enlarged as in MM. distinctus, the breadth to the length 
in the former being as 19:14, and in the latter as 19:13. The 
lateral margins present three incisions, so that four teeth are 
formed; the first incision is much deeper than the others. The 
first tooth or external angle of the orbits is a little shorter than 
the second, whereas in J. distinctus the second is a little 
shorter than the first. In both species the front is scarcely 
shorter than the epistome; the median part of the latter, how- - 
ever, is still visible when the carapace is viewed from above. In 
the form and the size of the front, and in the strueture of the 
upper surface of the cephalothorax, both species are identical. 
The infraorbital ridge is characteristic of this species, but it 
differs in the maleand inthe female. In the male it is continued 
backwards nearly to, or a little beyond, a point opposite the 
second lateral incision, and is composed of 25 lobules, of which 
only six constitute the orbital portion, the remainder being post- 
orbital. In younger specimens, the lobules which constitute the 
orbital portion are more numerous. These structures are com- 
paratively much larger in this species than in IZ. distinctus, and 
decrease less gradually but more rapidly in size and length. 
Each lobule presents at its posterior end a much smaller accessory 
