DUTCH BORNEO-EXPEDITION. 59 



regional grooves are, at least on the anterior half of the 

 upper surface, quite distinct and moderately deep in M. 

 granulosa, but they are almost wanting in M. Fornasinii', 

 the mesogastric furrow that bifurcates posteriorly, reaching, 

 however, only till the middle of the gastric region , is 

 faintly indicated and so also the lateral portions of the 

 cervical suture, the grooves between the gastric region 

 and the anterior branchial one , but other grooves are not 

 to be seen. In M. granulosa the regions of the upper surface 

 before the line that unites the antero-lateral teeth of the 

 last pair with one another, are distinct and well- 

 defined, more or less prominent and covered 

 with coarse granules, but the interregional grooves 

 and furrows are smooth ; in M. Fornasinii on the contrary 

 the regions are scarcely distinct, inconspicuous, and 

 the whole upper surface of the cephalothorax appears 

 smooth to the naked eye. Only when the carapace 

 is examined under a strong magnifying glass, one observes 

 a minute granulation near the antero-lateral and on the 

 postero-lateral margins, on the frontal teeth, on the upper 

 margin of the orbits and on the epigastric lobes. In both 

 species, immediately behind the frontal teeth of the second 

 pair, a small tubercle is present; this tubercle is less cons- 

 picuous, more rounded in the species described by Bianconi. 

 The general shape of the chelipedes is the same in both 

 and even as regards the form and the toothing of the 

 fingers , M. Fornasinii agrees with M, granulosa. These legs, 

 however, are everywhere quite smooth in Bianconi's 

 species, but conspicuously granulated in M. granu- 

 losa, as has been described in my Report on the Crustacea 

 of the Mergui Archipelago. The chelae of M. Fornasinii 

 appear, however, distinctly punctate to the naked eye; 

 these puncta are more numerous and somewhat larger 

 on the upper margin of the palm than on its convex 

 outer surface and between them a much finer microscopical 

 punctulation is moreover observed, when the legs are exa- 

 mined under a strong lens. 



Notes from the Leyden IMuseum, Vol, XXI. 



