146 DR. J. Ge DE MAN ON THE PODOPHTHALMOUS 
in this species than in M. messor, and measures exactly two 
thirds of the distance between the external orbital angles, both 
in the male and in the female. Its anterior margin appears 
nearly straight, and is minutely denticulated along its whole 
breadth, the minute granules being, however, a little larger 
towards the angles. Like J. messor, the front is much de- 
clivous, but the postfrontal lobes are still less prominent, 
though resembling those of that species. On each side of the 
middle three lobes may be distinguished, but, as in JL. messor, 
the two external ones of each side are scarcely separated from 
one another, often appearing rather confluent. They are a 
little granular, but never present the transverse rugose lines 
which oceur on the postfrontal lobes and on the gastric region 
of If. messor. Except the postfrontal lobes, the whole upper 
surface of the carapace of MW. maculatus appears. everywhere 
smooth and bright, presenting nearly the same interregional 
grooves which occur in IL. messor and I. pictus, and they 
are likewise minutely punctate, especially on the postero-lateral 
regions, when seen under a lens. In both species the postero- 
lateral regions are provided with many oblique, elevated lines 
near the lateral margin. The male abdomen presents a form 
distinct from that of JZ. messor. The terminal joint is com- 
paratively much smaller, triangular, and nearly as long as broad 
at its base; the penultimate is nearly twice as broad as the 
breadth of the base of the terminal joint, has rounded antero- 
lateral angles, and is even a little broader than the fifth joint. 
The terminal and penultimate joints have the same length, 
whereas in MM. messor the former is a little longer than the ~ 
latter. In the latter species the abdomen has rather a triangular 
form, the sides converging towards the tip of the terminal 
segment; but in WM. maculatus the sides of the abdomen, except 
the terminal segment, are nearly parallel to one another. 
The chelipedes and ambulatory legs of this species present a 
remarkable resemblance to those of I. pictus, but differ from 
those of JZ. messor by several characters. 
The chelipedes are somewhat unequal, both in the male and in 
the female. The arms much resemble those of the two other 
species. Their acute upper margin is transversely rugose; the 
anterior margin is armed with five or six small obtuse tubercles 
along its proximal half and is dilated anteriorly into a crest, 
which is armed with some acute teeth. The under margin of the 
