184 ZOOLOGISCHE MEDEDEELINGEN — DEEL 1. 



both surfaces, but naked and without spine near the carpal end at the 

 inner surface. Inner surface of the fingers hairy. Dactylus with a large 

 tooth near the base; index regularly denticulate at the cutting margin, 

 without larger tooth. In the adult the immobile finger is curved down- 

 ward, in young specimens, however, this finger is in a line with the 

 inferior margin of the palm. Unlike nearly all other species of the genus, 

 M. latreillei is characterized by having a spine at the distal end of the 

 meropodites of the last legs, as in the preceding ambulatory legs. 



This species, which is distributed throughout nearly the whole Indo- 

 pacific region, is represented in the collection of the Museum only by 

 Hoffmann's type-specimen of M. Polleni, from the Bay of Sakatia, Mada- 

 gascar. Its carapace is nearly wholly equilateral, the breadth between the 

 outer orbital angles being 32 mm., the length 30 mm. Though it is naked, 

 except for some hairs in the grooves, Ortmann's specimen of M. laniger 

 with a carapace-breadth of 41 mm. and a length of 28 mm. is wholly 

 covered by hairs. The carapace may be much more elongated transversely, 

 though not so as in the next species. Milne-Edwards mentions a specimen, 

 the carapace of which attains a breadth of 50 mm., a length of 35 mm. 



M. dentatus Stimpson. 



1858. M. dentatus Stimpson. Proc. Ac. Nat. Sc. Philadelphia, v. 10 p. 97 



(Hongkong). 

 1907. „ dentatus Stimpson. Smithson. Inst., Miscell. Coll., v. 49 p. 96, 



pi. 15 f. 1 (Hongkong). 

 1910. „ dentatus Rathbun. K. Dansk. Yid. Selsk. Skr., 7. Raekke, v. 4 



p. 322 (Gulf of Siam). 



The present species is placed next to M. latreillei on account of its 

 having also four lateral carapace-teeth in all, but in other respects the 

 general form of the carapace is much more like that of M. convexus, 

 though the transverse diameter of the carapace is less (length to breadth 

 as 1 : 1.67 according to Stimpson). This carapace is naked, without hairs, 

 smooth ! ), „except towards the postero-lateral angle, where there are two 

 slightly raised, plicated longitudinal ridges" (Stimpson, 1907). In the 

 figure there appear indeed on each branchial region two parallel rows 





1) The figure 3c of Laurie (see the list of synonyms of the preceding species) very much 

 recalls the present species in general form; yet the chief difference between such transversely 

 elongated specimens of M. latreillei and M. dentatus is to be found in the surface of the cara- 

 pace being distinctly granular in the first species and smooth in the latter. Besides, in M. den- 

 tatus the fingers of the chela are comparatively shorter, and both fingers have a larger tooth, 

 whereas such a tooth is wanting at the index of M. latreillei. 





