266 Capt. Lynes on the Ormtkotugy . [Ibis, 



done in Central Marocco by the Survey Departments (inci- 

 dentally considerably lowering many of the peaks, e. <j., 

 Jebel Aiachi from circa 14,100 to 12,300 feet, etc.), and in 

 some dozen French works * on Marocco the geology of this 

 region is discussed, though admittedly with much speculation 

 owing to scanty material; but in works accessible to the 

 general public (if anywhere ?) its Biology, save for a little 

 economic botany, remains as yet a blank. 



It is thought, therefore, that a slight digression from our 

 own particular branch will here be permissible, and that the 

 reader will find the following little resume of what has been 

 published up to date about the Physical Geography of the 

 Middle-Atlas of use in following later, a few speculations 

 on the wider subject of Geographical Distribution in 

 Mauretania. 



(a) Geoloijy. 



[I wish here to acknowledge tlie kind lielp of Mr. I'ampbcll-Smith, of 

 the British Musenni, to A\hom 1 submitted my small collection of 

 minerals, but, alas I no fossils.] 



Broadly speaking, the Middle-Atlas consists of the chain 

 of mountains, mountain mai^ses, and high plateaux extending 

 in a north-easterly direction for some 220 miles from (about) 

 Demnat in long. 7° W. ; terminating, to the eastward in 

 the valley of the jMiddle M'lonya, and to the northward near 

 Taza. For its western 80 miles, viz., from Demnat to the 



0. el Abid ^, , . ■ ^^ ^ ^ . ^^ , < , 



water-parting ^ -.., tlie chain is linked to the Great- 



^ '^ 0. M ionya 



Atlas, and ap])ears to be more a tumble of mountains and 



mountain spurs accessory to the latter, than a separate chainf. 



The Great-Atlas then bends away about 15 degrees to 



the southward, while the IMiddle- Atlas continues for the 



remainder of its l-lO-mile easterly stretch, as a chain of its 



* Louis Gentil, " Le Marocphysique," 1912, and several papers in 

 "Comptes reudus," 191o, 16; other authors are Ilohlfs, Pitard, Bernard, 

 De Foucauld, Segouzac, etc. 



t In similar manner the complementary chain called the "Anti- Atlas" 

 is linked to the Great- Atlas on its south side, and French geologists 

 consider the Lesser- and Anti-Atlas as fundamentally the same earth- 

 crinkle. 



