AND BATEACHIAXS OF BAEBAKY. 95 



that of the borders of the Mediterranean, and differs but little from that of the Spanish 

 aud Italian peninsulas. The Plateaux, consisting mostly of nude steppes with a mean 

 altitude of 2000-3000 feet, is the zone comprised between the Tell and the Sahara, 

 and presents in its fauna a mingling of Northern and Southern forms. Geryville, 

 Laghouat, and Biskra are exactly on the limit of the Plateaux and the Sahara. Towards 

 Oran the Plateaux extend almost to the sea-coast. The Sahara, south of the Great 

 Atlas, and extending uninterruptedly from the Atlantic Ocean to the valley of the Nile, 

 has an altogether special fauna, only a few of the forms of the Tell [Bana escidenta, 

 Bufo viridis, and Tropiclonotus viperinus, for instance) extending into its northern 

 portion. But this distinction applies only to Algeria; the Plateaux, which to the 

 west are limited by the north-eastern ramifications of the Great Atlas of Morocco, form 

 towards the east a wedge which culminates in the east of the Province of Constantine, 

 so that in Tunisia the Tell passes directly into the Sahara, and we consequently obtain 

 in Southern Tunisia a mingling of certain forms which in Algeria, separated as they 

 are by the range of plateaux, are characteristic of either the one or the other district. 

 The lofty Atlas of Morocco separates the Sahara from the plain of Morocco, which to 

 the north and north-east passes into the Tell proper and is completely cut off from the 

 Plateaux ; this plain having a distinct fauna, deserves to be dealt with separately, and 

 I propose to allude to it as the Moroccan district. Its fauna is still very imperfectly 

 known, the only places at which herpetological collections have been made being 

 Casablanca, Mogador, and the route from Mogador to Morocco. A few forms are 

 known from the valley of Sous, but of the Great Atlas proper we know nothing. 

 Hooker and Ball, remarking on the scarcity of animal life as a characteristic feature 

 of the Great Atlas, state that "of the numerous Reptiles that abound about the skirts 

 of the mountain-range, few, except Lizards, seem to frequent the interior valleys ; and 

 the latter are wanting, or at least rare, in the higher region." Of Eastern Morocco we 

 likewise know absolutely nothing. But the northern promontory, which bears Tangier, 

 Ceuta, and Tetuan, has been tolerably well investigated, and forms altogether so distinct 

 a feature in the fauna of Barbary that it deserves to be recognized as the Tangitanian 

 district. There we meet with species otherwise peculiar to the Moroccan district, 

 and with a few endemic forms, but with comparatively few, except the most widely 

 distributed, that are identical with those of the Algerian Tell ; and, what is still more 

 surprising, no more special affinity is shown to the fauna of Southern Spain than in the 

 latter district, with the only exception of the occurrence of Molge waltlii. 



Barbary is therefore divided into five districts, viz. : — 1, The Moroccan ; 2, the Tan- 

 fiitanian ; 3, the Tell ; 4, the Plateaux ; 5, the Sahara. In addition to these districts, 

 the political divisions of Oran, Algiers, Constantine, and Tunisia are adopted to serve as 

 landmarks in the distribution from West to East of the species shown, as far as present 

 knowledge permits, in the following Table. 



