XII. TERTIARY FISH-REMAINS FROM SPANISH GUINEA 

 IN WEST AFRICA. 



By C. R. Eastman. 



Plates XXIII-XXIV. 



In May, 191 1, a shipment of natural history specimens was received 

 by the Carnegie Museum which had been collected by Rev. A. I. 

 Good, a missionary stationed at Benito, in Spanish Guinea, and by 

 him forwarded to Director W. J. Holland in the fall of 1910. 



The collections made by Mr. Good for the Carnegie Museum are 

 chiefly entomological, but, included among the lot of insects and other 

 objects illustrating the natural history of the region, were found a 

 number of slabs of dark-colored fissile shale, containing an abundance 

 of carbonaceous matter, with here and there a few small-sized con- 

 cretions, valves of Entomostraca, and portions of Teleost fish-skele- 

 tons, these last being comparatively numerous. 



The amount of carbonaceous matter present in the rock is so great 

 that the shales might properly be called bituminous, and appearances 

 indicate very strongly that they are of lacustrine, or perhaps estuarine 

 origin, certainly not marine, and were deposited in a rather shallow 

 basin. No means are at hand for determining the geological age of 

 the strata except the evidence furnished by the remains of the fishes 

 embedded within the shale, and they betoken an early Tertiary 

 horizon, probably at least as early as the dawn of the Eocene. The 

 geology of the region about Benito has not been studied or described, 

 so far as the writer is aware, but it is a well-known fact that isolated 

 patches of Tertiary rock occur frequently along the eastern and 

 western coasts of Africa, and their distribution is indicated in a general 

 way by Walcot Gibson in a sketch-map of the geology of the continent 

 to be found in the first volume of the new Encyclopedia Britannica. 1 



1 The marine strata of the early Tertiary of South Togo, in West Africa, have 

 furnished a number of vertebrate remains which are described by Dr. Ernst Stromer, 

 of Munich (Zeitschr. deulsch. geol. Ges., Vol. LXII, 1910, pp. 478-508). More 

 recently the same writer has contributed a note entitled "Funde fossiler Fische in 

 dem tropischen Westafrica" (Centralbl. f. Min., etc., Jahrg. 1912, no. 3, pp. 87, 

 88), which mentions the discovery of fragmentary Teleost and Silurid fish-remains 

 from near the mouth of the River Benito in Spanish Guinea, without, however, 

 offering detailed descriptions of them. 



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