544 COL. XEB.BURY AND MB. O. THOMAS ON [June 18, 



is a good deal of cultivation in the bed, but the greater part of it is 

 choked up ^^'ith a growth of gigantic reeds. Away from the bed 

 of the river the country on both sides is an absolute desert. About 

 eight miles beyond Zaidah the outlying spurs of the mountains are 

 reached. The rise of the land between the Barrier Gate and 

 Zaidah is probably under 100 feet; the cliffs at Haithalhim and other 

 places are quite 40 feet high, showing that the river has cut itself a 

 bed to this depth in the soft soil. 



The places collected at were Aden, Shaik Othman, Lahej, and 

 Haithalhim, and all these places may be considered of the same 

 altitude. Aden itself, i. e. the peninsula, is entirely composed of 

 volcanic rock. The mammals are Monkeys, Foxes, an occasional 

 Jackal, two species of Rat, a spiny Mouse, two species of Shrew, 

 several species of Bat, and probably the Common Mouse, the 

 Musk-Rat, and a species of Bandicoot. The greater part of the 

 maritime plain inland has been at some period under the sea, but 

 round Lahej a great amount of detritus brought down by the river 

 has been deposited. The Arabic names of the various mammals 

 met with are as follows : — 



Monkey : rubba. 



Fruit Bats : sir, or, perhaps nearer, the " Zumerset " zurr. 



Nycterls thebaica : choef, probably applied to all small Bats. 



Fox : darain ; occasionally taleb. 



Hare : drnub. 



Hyena : dheb. 



Porcupine : r/endebah. 



Gazelle : dobbi. 



Ibex : luedl. 



One other place may be worthy of notice, and that is the island 

 iu Ras Fakoum Bay beyond Little Aden. On this island is a large 

 cavern, large enough to admit a ship's gig, which swarms with Bats. 

 Three species were obtained there — Coleura afra in small colonies by 

 therase\yes,a,ndlfipposidei'os tridensandi Tricenojjs persicus mixed up 

 together. As the cave is lofty, aU specimens have to be shot, and 

 the walls of the cave rising straight out of the sea the specimens 

 when shot fall into the water ; this of course does not improve them 

 as such. 



One word as to the names of places visited : the name of the Arab 

 town inland from Aden is Al Hautah, while the name Lahej appears 

 applicable to the whole of the territory of the AbdaU Tribe ; but as 

 it is always customary to talk of the town as Lahej, we have done 

 80 here. 



All the specimens mentioned in this paper have been presented 

 to the British Museum. 



The determination of Arabian mammals presents in some ways 

 unusual difficulty, owing to the fact that the Indian and African 

 faunas meet here, and that species described from each, without 

 reference to the other, often prove to be unexpectedly similar. 

 Arabian animals may therefore often be apparently with equal 



