78 CARCINOLOQICAL STUDIES. 



upper margin of the mobile finger of Macr. dila- 

 tatus is straight and distinctly granulated; the inner 

 margin has numerous very small teeth , but no large 

 prominent one. The inner margin of the index presents 

 also numerous very small teeth and no large one. In 

 Macr. crassipes the dactylus is rather strongly 

 arcuate and smooth, even at the upper mar- 

 gin; the inner margin presents some small teeth, of which 

 one quite at the base is a little larger. The immobile 

 finger is armed with a prominent tooth in the 

 middle of its inner margin , the tip of which tooth descends 

 obliquely to the proximal end of the finger and perpendi- 

 cularly to the distal end. The inner surface of the palm 

 is armed in both species with a spine and densely covered 

 with hairs, like the inner surface of the fingers. 



Macr. crassipes M. Edw. is also closely allied to Macr. 

 carinimanus Latr. The cephalothorax of the latter differs from 

 the cephalothorax of Macr. crasszpes especially by the less 

 oblique direction of the upper orbital margins, 

 so that the external orbital angle, which is directed 

 obliquely outward, projects as much forward as the 

 upper orbital margin, which is not the case in ilfacr. 

 crassipes. The incision which separates the external orbital 

 angle or first antero-lateral tooth from the second , is much 

 narrower in Macr. crassipes than in the other. Both species 

 resemble one another as regards the granulation and the 

 structure of the upper surface, and two granulated eminences 

 are observed on the postero-lateral sides in both forms. 



The hands of Macr. carinimanus (fig. 8) are however 

 longer and more slender than those of Macr. crassipes , 

 the palm being nearly four times as long as 

 high in the former, but only about twice as 

 long as high in the latter species. The proportion 

 between the length of the palm and of the fingers is about 

 the same in both forms. The outer surface of the palm is 

 finely granular above and towards the articulation with the 

 wrist , and presents below, near the lower margin, a strong 



Notes from tlae Leyden Miuseuxxi, "Vol. XII. 



