132 de. f. Oswald ox the [June 19 14, 



to 20) of the series, and eoprolites (probably Crocodilian) are 

 characteristic of these beds. No. 20 at Nira displays an interesting 

 instance of a contemporaneous water-channel in the underlying 

 clay, now filled up by a buff-coloured sandstone. 



Nos. 21 to 23 form another natural group, consisting of pale- 

 grey or even white sandstones, current-bedded, and sometimes 

 exceedingly hard. Towards the east they become argillaceous, and 

 even pass laterally into grey, clays (at Kikongo), mottled some- 

 times with red. Where the sandstone becomes gravelly, the 

 constituents are usually of grey sandstone (apparently derived from 

 older beds in the Miocene Series), together with quartz, ironstone, 

 green andesite, and pink gneiss. In the lower sandstone (No. 23) 

 of Nira I noticed a number of stvlolithic concretions, lvins: 

 adjacent one to the other, each consisting of spiral coats, and 

 probably due to some special conditions of contraction during 

 consolidation. As soon as the beds become more arenaceous fossils 

 occur more frequently, and in the hard sandstone (No. 22) of 

 Kachuku I found the tibia of a Proboscidean somewhat re- 

 sembling that of Dinotlierium, associated with Ampullaria and 

 a JPodocnemis. Cbelonian and Crocodilian remains occur in all 

 the sandstones of this series, and I was able to restore a nearly 

 complete carapace of Cycloderma victories (from about a hundred 

 pieces) occurring in the white sandstone of No. 21. 



Nos. 24 & 25 form a natural group, composed of a fine orange 

 gravel (No. 24) overlying a greenish-grey clay with seams of 

 cellular travertine. The gravelly sand is only a few inches thick 

 (3 to 9 inches), but constitutes a very definite horizon. It is of 

 special interest for containing teeth, not only of Crocodile and 

 I) in oilier hi m, but also of Protopterus ( which has not, I believe, 

 been found hitherto in a fossil condition) and of rodents similar 

 to JPhiomys. The underlying greenish-grey clay of No. 24 con- 

 tained opercula of Ampulla ria and fairly numerous shells of 

 Cleopatra exarata. The grey clay of No. 25 (sometimes reddish 

 towards the west) contains remains of Trionyx, eoprolites, and 

 part of a tusk, probably of Dinotherium. 



(3) The lower series (Nos. 26 to 37) includes beds of a 

 more torrential character than the preceding. 



Nos. 26 to 29 form a variable series (7 to 8 feet thick) of 

 sandstones and gravels, becoming coarser and more calcareous 

 towards the base ; the constituents comprise not only grey sand- 

 stone, quartz, pink gneiss, and green andesite, but also jasper. At 

 Kachuku No. 28 forms a coarse, nodular, calcareous conglomerate, 

 and most of the pebbles have a calcareous coating ; it often con- 

 tains large lumps (measuring up to 2 feet in diameter) of } T ellow 

 marlstone, evidently derived from a lower bed, enveloped in several 

 concentric coatings of carbonate of lime. Fossils are very sparing 

 and fragmentary in these gravels, and mainly consist of Chelonian 

 and Crocodilian remains with eoprolites and a fragment of Dino- 

 iherium-tvLsk. The beds of gravel are lenticular and inconstant, 



