130 ME. J. MAWSOX OX THE [-^ aV 1 9°7t 



The precise extent and boundaries of the Cretaceous basin of 

 Bahia still remain to be determined, but the accompanying sketch- 

 map (p. 129) bears the names of all the localities at which I have 

 discovered the typical fossils of the formation. A few notes on 

 some of the sections are appended. 



Montserrat, Pedra Furada, and Bomfim. — The general 

 features of this section have already been sufficiently described by 

 Allport. Gasteropod-shells are commonest and best preserved in 

 the ridges of sandstone at various points, and in the hard, fine- 

 grained, brownish limestone near Pedra Furada. Scales of Lepi- 

 dotiis and fragments of reptilian bones, mostly rolled, occur nearly 

 everywhere ; while complete examples of a small species of Diplo- 

 raystus have been found, in a very thin layer of compact greenish 

 mudstone, between Pedra Furada and Bomfim. In a large 

 calcareous concretion, in the shales near Bomfim, I once discovered 

 a nearly-complete specimen of Lepidotus. Beyond Bomfim north- 

 wards the Cretaceous deposits sink beneath low sandy flats, and 

 only reappear on the opposite side of the bay at Cabrito and 

 Plataforma. 



The Bahia- and - San Francisco Railway. — Cretaceous 

 strata are first seen on this railway between 3 and 4 kilometres 

 away from Bahia (Calcada Station). The Amioid fish Megalurus 

 Mawsoni, and numerous well-preserved entomostraca (described by 

 Prof. T. Rupert Jones x ) were found in shale on the beach just beyond 

 Kilom. 4. A bluish-grey sandstone in the railway-cutting is also 

 fossiliferous. Between Plataforma, Itacaranha, and Escada, the 

 beach has yielded more remains of fishes and reptiles than any 

 other section of the Bahia Cretaceous Series — among others, the 

 well-preserved skeletons of Diplomysius longicostatv^ and Chiro- 

 mystus Maivsoni, and the skull of the large new Ccelacanth fish, 

 JIaivsonia gigas. Teeth of crocodiles are abundant, as already noticed 

 by Allport. Large and small coprolites occur almost everywhere. 

 Entomostraca are also common, but mollusca are very rare, only 

 Planorbis having been found. Xear Periperi (kilom. 11) there are 

 very few fossils, but fragmentary vertebrate remains are common 

 again at Setubal (kilom. 12^). The shales between Olaria and 

 Mapelle (kilom. 22) are also fossiliferous, but they become too friable 

 on exposure. The hard conglomerate of Alapelle Quarry (near 

 kilom. 23) has yielded numerous dinosaurian and crocodilian bones, 

 besides remains of Maivsonia. At Agua Comprida (kilom. 29) the 

 shales and flaggy limestones are highly fossiliferous, and well- 

 preserved skeletons of Diplomystus longicostatus occur here. Between 

 Agua Comprida and Matta (kilom. 69) no fossils have been found ; 

 but a few occur again at rare intervals between the latter station 

 and Pitanga (kilom. 75), where a reddish and yellowish clay contains 

 freshwater bivalves. From Pojuca Tunnel (kilom. 78) to San Thiago 

 (kilom. 86) the characteristic shales, limestones, and sandstones 

 yield numerous vertebrate fossils like those of the beach near Bahia. 



1 ' On some Fossil Entomostraca from Brazil ' Geol. Mag. dec. 4, vol. iv 

 (1897) pp. 195-202 & pi. viii. 



