12 TRANSACTIONS OF THE WAGNER FREE 



Not much more than a quarter of a mile above Tampa, and just 

 below the ship-yard, a tough siliceo-calcareous rock, identical with that 

 found at Ballast Point, appears on the left bank immediately on water- 

 level ; the same rock is visible on the right bank at a further distance of 

 about a half mile, and reappears again at intervals of three, four and five 

 miles. There can be no doubt that it forms the bed of the stream for 

 this distance. It can be readily identified by its numerous Cerithium 

 remains, the same as we found impressed in the rock at Ballast Point. 

 At Magbey's Spring, a short piece above the ship-yard, we found water 

 issuing from a yellow and white limestone, containing numerous fossils ; 

 large sink-holes expose the fossiliferous limestone, crowded with shell 

 remains' and the Orbitolites Floridana, for an extent of some ten 

 feet. Owing to the very limited nature of the exposure I was unable 

 to determine its true dip, but as the locality is distant not more than a 

 few hundred feet from the river, and rises above it some fifteen or twenty 

 feet, there can be no doubt that the rock in question overlies that which 

 appears immediately on the river front, and which, as has already been 

 said, almost positively forms its bed for a distance of several miles. In 

 this section, therefore, we have established the relation existing between 

 the two rocks exposed at Ballast Point. The locality at Magbey's Spring 

 is the only one on the Hillsboro River where we observed the Orbito- 

 lite limestone. 



During the day's journey my attention was called to an individual 

 of the Florida " mud-puppy," but I was unable to approach the animal 

 sufficiently near to determine whether it was a Necturus or not. Turtles 

 were surprisingly abundant, and their splash, when dropping from an 

 overhanging bough, could be heard at frequent intervals around the turns 

 of the stream. Nine individuals, of possibly more than one species, were 

 seen on a single raft, sunning themselves in pleasant ignorance of im- 

 pending danger. I much regretted not being able to visit the falls of the 

 Hillsboro, about three miles beyond the furthest point reached in our 

 exploration, where the ledge .of rock over which the water is precipitated 

 is said to be largely coralliferous, and of the same character as that 

 observed at Ballast Point. 



MANATEE RIVER. We left Tampa toward evening, pushing off with 

 falling tide, and headed for the Manatee River. The dredge was thrown 

 over in the mouth of that stream, and struck on an Anomia bank. The 

 dead shells of Venus cancellata were brought up in great quantity, together 

 with a number of crabs, a species of Lima, and several individuals of the 

 common sea-urchin of this part of the coast, Toxopncustes varicgatus ; 

 depth of water about 12 feet. 



It was our intention to explore some of the islands in Terraccia 



