CARCINOLOGICAL STUDIES- 61 



This species is most closely allied to Pilumnus actum- 

 noides A. Milne Edw., which inhabits New Caledonia , but 

 in this form the frontorbital margin of the upper surface 

 of the carapace is comparatively broader, according to the 

 figure published by Milne Edwards, the small teeth of the 

 antero-lateral margins are more numerous and more pro- 

 minent , and the outer surface of the larger hand is covered 

 with less numerous granules. The dactylus of Pilumnus 

 actumnoides seems to be also a little more granulate above. 



Pilumnus globosus was discovered by Dana at the island 

 of Tahiti and at some other islands of the Pacific Ocean , 

 and was observed by the Challenger Expedition in the 

 Japanese Seas. 



11. Pilumnus tahitensis, n. sp. 

 (PI. 3, fig. 4). 



Two specimens (cf and Q) from Tahiti. 



This very interesting new species may at first sight be 

 distinguished from its numerous congeners by the fingers 

 of the chelipedes which have exactly the same structure as 

 those of Pilumnus cristimanus A. Milne Edw., and by the 

 antero-lateral margins of the carapace being armed with 

 the typical number of acute spines, just as in the typi- 

 cal forms of the genus. 



The cephalothorax is a little broader than long. Its 

 upper surface is rather depressed , only declivous towards 

 the front and slightly so towards the antero-lateral mar- 

 gins. The regions are not or very faintly indicated; the 

 upper surface appears smooth and shining between the 

 scattered tufts of hair, but slightly uneven , though scar- 

 cely distinguishable , at the insertion of every tuft of hairs. 

 The hairs, with which the upper surface is covered, are 

 partly long , silken and pale yellowish , partly pinnate. 

 They arise in transverse rows on the front at some dis- 

 tance from the margin. The front is rather prominent, 

 less broad than half the breadth of the cephalothorax, 



Notes from tlie Leyden Museum, Vol. XII. 



