146 DB. J. Gt. DE MAN ON THE PODOPHTHALMOtS 



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 M. messor, the front is much de- 

 cliyous, 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 M. messor, 

 the two external ones of each side are scarcely separated from 

 one another, often appearing rather confluent. They are a 

 Kttle granular, but never present the transverse rugose lines 

 which occur on the postfrontal lobes and on the gastric region 

 of M. messor. Except the postfrontal lobes, the whole upper 

 surface of the carapace of M. maculatus appears everywhere 

 smooth and bright, presenting nearly the same interregional 

 grooves which occur in M. messor and M. pictv,s, 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 M. 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 M. 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 M. onaculatus 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 M. pictus, but differ from 

 those of M. 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 



