Bathbun.] 242 [December 16, 



capped with a bed of unconsolidated tertiary sand, and both the 

 clays and the limestone composing it are probably of cretaceous age. 



Following up the river along the north side for about a mile, we 

 come upon a rather heavy bed of hard, whitish limestone, outcrop- 

 ping from the plain near the bank of the river, and containing creta- 

 ceous fossils, mostly lamellibranchs. It is covered with tertiary de- 

 posits. This stone is extensively burned for lime and may be desig- 

 nated the Maria Farinha bed. On the south side of the river, about 

 midway between its mouth and Maria Farinha, and a short distance 

 from its bank, is a slight exposure of fossiliferous cretaceous lime- 

 stone, resembling the limestone bed in the cliff at Pt. Nova Cruz. 

 Only the upper portion of a single layer projects from the tertiary 

 plain. To this bed has been given the name Sao Jose. 



As far as could be ascertained, the beds at Sao Jose and Pt. Nova 

 Cruz are horizontal, while the Maria Farinha bed has a slight dip to 

 the west, only observable in large exposures of the rock; but the 

 relative horizon of the beds of the three exposures could not be de- 

 termined, as the surface is everywhere covered with loose materials. 



A careful comparison of the fossils obtained from them has shown, 

 however, that although none of the species, so far as known, occur in 

 all three beds, yet some are common to both the Pt. Nova Cruz and 

 Sao Jose localities, while others are found in the Maria Farinha and 

 either the Sao Jose or Pt. Nova Cruz beds. The character of the 

 rock in the three exposures is also quite similar, all uniting to prove 

 the close relationship of the beds, which may belong near the Sergi- 

 pian and Cotinguiban groups of Prof. Hartt. The beds at Pt. Nova 

 Cruz and Sao Jose seem to be more nearly related to one another, 

 than do either of these to the one at Maria Farinha. The limestone 

 containing the fossils is somewhat porous, and, being constantly ex- 

 posed to the weather, the shells have been entirely removed by the 

 percolation of water, thus leaving only the moulds of the exterior 

 and interior, some of which are very perfect. 



Lamellibranchs are by far the most abundant fossils in all three lo- 

 calities. At Point Nova Cruz and Sao Jose, gasteropods and cepha- 

 lopods are quite common, the latter often of considerable size, but in 

 a poor state of preservation. Some few fish and crustacean remains, 

 together with a single echinoid and fragments of a small coral, were 

 also found. On the island of Itamaraca, three or four miles above 

 the mouth of the Rio Maria Farinha, there is exposed a bed of soft 



