's RIJKS MUSEUM VAN NATUURLIJKE HISTORIE — LEIDEN. J 73 



row of verrucous tubercles on the branchial regions. The transverse 

 furrows on the carapace are much less pronounced. The general form of 

 the carapace is much like that of M. dilatatus, but the external orbital 

 angle projects less outward than the anterior lateral tooth which is larger 

 and directed obliquely forward, as shown in the figure. 



The specimen of the Museum agrees exactly with Hilgendorf 's figure, 

 but the front is somewhat broader. The ocular peduncles reach to the 

 tip of the external orbital angle; according to Hilgendorf they are twice 

 as long as the front between the eye-stalks (though it does not appear 

 so in his figure, in which the latter are three times as long as the front) ; 

 in my specimen the length of the eye-stalks keeps an intermediate place 

 between Hilgendorf's description and figure. 



The main character of the species is again to be found in the male 

 cheliped. The arm bears a thick fur of hairs on the inner side ; the wrist 

 has only one spine, at the under side, near the articulation with the palm, 

 but none at the inner border; the palm is much less elongated than in the 

 preceding species, its length being scarcely twice the height, the outer 

 surface has a very distinct ridge near the under margin and is slightly 

 granular towards the upper margin, which shows a regular row of spini- 

 form tubercles; the inner surface of palm and fingers is much hairy 

 and there is a spine near the carpal end. The cutting margin of the 

 movable finger is, as has been rightly observed by Hilgendorf, concealed 

 by a closely set hairy covering, on close inspection we may see a distinct 

 rectangular tooth near the base of the finger, which tooth does not seem 

 to have been detected either by Hilgendorf or by de Man. The cutting 

 margin of the index is free from hairs and the proximal half is occupied by 

 a large tooth, crenulated on the free margin, except for the abruptly sloping 

 fore side. In the preceding species this tooth on the index has a much 

 smaller base and is more distinctly sloping towards the base of the finger. 

 This East-African species is represented in the Leiden Museum by 

 a single specimen (<ƒ) from the Bay of Pasandava (Madagascar); it has 

 been already spoken of by de Man. 



Its dimensions and those of Hilgendorf's specimen from Zanzibar are 

 the following : 



Distance between external orbital angles . . 22.5 32. — 



Length of carapace 11.5 15.^ — 



Breadth of front between the eye-stalks. . . 3.5 — 



Length of the palm with index . . . . . 14. — l ) 23. — 

 Height of the palm 6. — 



1) de Man gives a length, of 15.5 mm. to the hand, but I cannot explain this, unless it be 

 presumed that the author has measured to the tip of the opened dactylus. 



