1900.] A. Alcock — Carcinological Fautm of India. 449 



The abdomen in both sexes consists of 7 separate segments, and 

 in the male its base covers all the breadth of the sternum between the 

 last pair of legs. 



The gill-chamber and its lining membrane, and the number of 

 branchiae, are as in Cardiosoma. 



The Pelocarcini are land-crabs. The single Indian species is very- 

 corn mon in the jungles of the Andamans, where, especially on the 

 smaller islets, it grows to a large size. 



Distribution : Brazil, Andamans and Nicobars, Celebes, Philippines, 

 New Guinea, Loyalty Is. 



Ortmann (I.e.) throws doubt on the locality Brazil, buf, as ifc 

 appears to me, without sufficient reason, seeing that the elder Milne 

 Edwards states definitely that the type of the species was found in 

 that country by a collector of the Paris Museum. Pelocarcinus is by 

 no means the only form of animal life that has this very curious and 

 suggestive distribution, which we also find, among Mammals in the 

 Tapirs, among Birds, as Mr. Finn informs me, in the Piculets of the 

 genus Picumnus, among Reptiles in the Ilysiidze, and among fishes in 

 the freshwater eels of the genus Symbranchus. 



130. Pelocarcinvs Humei (Wood-Mason). 



Hylxocarcinus Humei, Wood-Mason, Jonrn. As. Soc. Bengal, Vol. XLII. 1873, 

 pt. 2, p. 260, pis. xv, xvi, and Ann. Mag. Nat. Hist. (4) XIV. 1874, p. 190. 



Carapace transversely oval, becoming broader with age, its lateral 

 borders tumid and ill defined. The gastic region is particularly well 

 delimited and is divided into three subregions — two antero-lateral and 

 one postero-median — the anterior two of which are separated from one 

 another by a deep groove : the cardiac-intestinal region is fairly well 

 defined. 



In adults the carapace is smooth, except for some oblique striae on 

 the lateral borders, which become squamiform markings on the ptery- 

 gostomian regions, these regions being devoid of tomentum. 



Front nearly vertically deflexed, somewhat spatulate but with the 

 free edge straight. The tooth at the inner angle of the orbit does not 

 usually touch the front, bnt sometimes it does and excludes the small 

 antennse from the orbit. 



The chelipeds in the adult male are usually equal and are about 2| 

 times the length of the carapace : the arm projects a long way beyond 

 the carapace, and its upper and inner borders are rugose or irregularly 

 tuberculate; the inner angle of the wrist is truncated; the palm is en- 

 larged, its length is about \\ times its height and about as long as the 



