336 Correspondence — Rev. 0. Fisher — Mr. J. S. Gardner. 



it was supposed to have died out, or to have been overlapped by the 



Woolwich Beds. 



We have prepared some interesting new sections in the Lower 



Tertiaries around Epsom, which we hope to publish shortly. 



Caeshalton, Surrey, Sydney B. J. Skertchly. 



May 10th, 1886. 



MEMORANDUM FOR GEOLOGISTS VISITING WEYMOUTH. 



Sir, — Driving from Weymouth the other day, I noticed some 

 magnificent blocks of the cherty flint of Bincombe Down, 1 placed to 

 be broken up for mending the road. This shows that the part of the 

 Lower Eocene bed there is now open which contains these blocks. 

 I would strongly advise any geologist visiting Weymouth, who is 

 conversant with the Cretaceous series, to examine these blocks. If 

 I am not mistaken, they represent some horizon which has entirely 

 disappeared from the area. It does not seem to me quite certain 

 whether they are flints, altered in texture, or whether they are 

 chert. In shape and size they are like those which are and have 

 been worked for implements at Brandon ; but in texture they are 

 quite different, being grey throughout and opaque, with many casts 

 of fossils. Similar flints, containing similar fossils, occur in the 

 extraordinary flint bed resting upon the Greensand of Haldon Hill, 

 near Exeter : and there is a collection of the fossils in the Exeter 

 Museum ; as there is also a small collection of the Bincombe fossils 

 at Dorchester. 



The observer must not be deceived by certain flints to be seen in 

 walls, etc., along the Weymouth road, which are not chalk flints, 

 but come out of the Portland beds at Bincombe. They are usually 

 nearly spherical in shape, and black inside. 0. Fisher. 



DOES TEREDO INHABIT FRESH WATER? 

 Sir, — I have found an account by Dr. E. P. Wright of a new Teredo 

 which he names Nausitoria from the Ganges, in the Linnean Soc. 

 Trans. 1864, p. 451. It is found in the river Comer, a loop which 

 runs separately from the Ganges for 80 miles, when it rejoins the 

 main river at Mandarapore, 70 miles from the sea. The water for 

 30 miles below Mandarapore is perfectly fresh, when it becomes 

 slightly brackish at full tide ; but in the Comer it is always quite 

 fresh and soft and used for drinking, washing, etc. Trees and boats 

 are however attacked by a Teredo in it, and hence Dr. Wright be- 

 lieves that at all events this species does live in perfectly fresh 

 water. J. S. Gardner. 



1 See Damon's Geology of Weymouth and Portland, 2nd edition, p. 143. 



