1869.] BLANPORD ABYSSINIA. 403 



succeeded by limestone, as already mentioned at Dongolo ; but near 

 Adigrat it underlies trap, probably of the Magdala group, with ap- 

 parent conformity. 



Antalo limestone. — The next group in ascending order consists 

 chiefly of limestone ; and in this, for the first time, fossils occur in 

 some abundance. The rock is pale-coloured and usually well stra- 

 tified ; it occupies the line of route taken by the British force for 

 about 70 miles from Dongolo till south of Antalo. To the north 

 scarcely any other beds are inters tratified ; but further south, es- 

 pecially near Antalo, both sandstones and traps are met with, the 

 latter being always doleritic, and a portion of the bands being, to 

 all appearance, contemporaneous. The uppermost part of the for- 

 mation is of sandstone and conglomerate, which are best seen in the 

 Mishek valley south of Antalo. 



These hmestones have been very well described by Messrs. Ferret 



ind Galinier, who quite rightly attributed them to the Jurassic 



formation. Although fossils abound, it is singularly rare to find 



any in sufficiently good preservation for accurate determination ; but 



amongst those obtained are the following : — 



Hemicidaris, sp, nov., near H. Licciensis, D'Orb., and H. Wrightii, Cotteau. 



Trigonia costata, var. pulla, Sow. 



Modiola Baini, Sharpe, or a closely allied species. 



Ceromya concentrica, Sow. 



C. similis, Sow. 



C, sp., perhaps a var. of C. excentrica, Sow. 



Pholadomya sp., near Fh. recurva, Ag., and P. concatenata, Ag. 



Ph., sp. near Ph. (Panopcea) punctifera, Buv. 



Alaria, sp. 



Cerithium, sp. 



and numerous casts of bivalves. 



Other forms occur ; but the above are the most characteristic. 



Trappean series. — Nearly all southern Abyssinia, with Shoa, is 

 known to consist of bedded traps ; and although they do not occupy 

 so extensive a surface in Tigre, they nevertheless cover a very con- 

 siderable tract. 



On the road to Magdala volcanic rocks were met with at Senafe, 

 where several hills consist of basalt and trachyte. The latter passes 

 into a claystone which simulates sedimentary rocks to a remarkable 

 extent, and forms the singular bosses known as Senafe rocks, which 

 were mistaken for sandstone by almost all observers ; indeed I was 

 myself deceived at first. Near Adigrat is a great range formed of 

 horizontal beds of basalt, and probably, in the upper portion, which I 

 had no opportunity of visiting, of trachyte ; but it was south of 

 Antalo that the great trappean area was entered, and traversed 

 by the route of the army, without a break, to Magdala. 



This trappean series plainly consists of two groups, the upper of 

 which was clearly seen resting unconformably on the lower in the 

 valleys of Atala and Ayba south of Antalo. The lower division I 

 propose to call the Ashangi group, from its great development 

 around the little lake of that name ; the higher the Magdala group. 



