388 Professor A. C. Seivard — 



western base of Kilulu and Kirimba hills. The direction of the 

 fault is about N.N.E., that is parallel with the coast, and the sandstone 

 here dips at a high angle to the east in contrast to the prevailing 

 dip elsewhere. 



" A moderate estimate indicates a thickness of at least 10,000 feet 

 of sediments in this region." 



Description op th^ Specimens. 



Two of the specimens, though not in my opinion of vegetable 

 origin, are sufficiently interesting to be briefly described. 



A slightly raised portion of the rock, approximately circular in 

 outline and differing from the rest of the matrix, shows a smooth 

 border and, in the central region, a very indistinct division into a 

 few cuneate radially disposed areas. In one specimen the circular 

 body is 9 cm. in diameter ; it is bounded by a well-marked line or 

 low ridge, which forms the edge of a very slightly depressed smooth 

 border, rather less than 1 cm. broad. This smooth border surrounds 

 a central area, exhibiting vaguely a radial disposition of segments 

 similar to those in the smaller specimen. 



Except in their smaller size, the specimens resemble a supposed 

 fossil alga described by Walcott,^ from Algonkian rocks in Montana 

 as Gallatinia pertexa, which, I venture to think, is a fractured 

 septarian nodule. Comparison may be made also with impressions 

 of Medusae, e.g. Rhizostomites admiranda Haeck,^ from the litho- 

 graphic slate. "Wfiile favouring an inorganic origin, I suggest that 

 the specimens are worthy of examination by a palseozoologist. 



Planta iNCERT^ SEDis. ? Eretmophyllum sp. Plate XVII, Fig. 1. 



This specimen shov/s the impression of what appears to be a thick 

 leaf with a linear sessile lamina 7 cm. long, not quite complete at 

 the distal end : the apex was probably obtuse ; it is longitudinally 

 striated and in addition to the striae, the expression probably of some 

 fibrous tissue, there are a few prominent longitudinal ridges about 

 1 mm. apart, which diverge and fork from the base, and probably 

 mark the position of veins. It is difficult to assign this specimen to 

 a precise systematic position ; while superficially resembling some 

 leaves of Schizoneura figured by Feistmantel ^ from Gondwana 

 beds in India, the agreement is by no means sufficiently close to 

 justify inclusion in that genus. It resembles also detached leaves 

 figured by the same author from Jurassic (Upper Gondwana) rocks 

 in India,** and referred on insufficient evidence to the Jurassic 

 European species Podozamites lanceolatus Lind. and Hutt. The 

 Tanga specimen is, I am convinced, not a leaf of Podozamites. It 



1 C. D. Walcott, " The Precambrian Algonkian Algal Flora " : Smithsonian 

 Miscell. Coll., vol. Ixiv, No. 2, 1914, pi. xxiii. 



2 K. A. von Zittel, GrundzUge der Paleoiitologie, 1895, p. Ill, fig. 216. 



3 Feistmantel, Foss. Flor. Gondwana system, vol. iii, pt. ii, 1880, pis. iA, etc. 

 * Ibid., vol. iv, pt. i, 1882, pi. ii, fig. 6. 



