12 MR. E. A. NEWELL ARBER ON THE UPPER [Feb. I907, 



well seen in the cliffs, their entire length often not exceeding 

 5 feet, while some are not more than 2 feet long. They vary 

 from 4 to 10 or 12 inches at their greatest width, and thin out to less 

 than an inch at either end. The light-fawn colour of the weathered 

 surface of the bands when dry, and their deeper, brown colour when 

 wet, renders them conspicuous against the dark shales prevailing 

 in this region. 



Search has been made for similar lenticular bands farther west- 

 ward, in the direction of Clovelly, but they have not been observed 

 so far. One was recognized in Cornwall, however, on the north 

 side of Lower Sharpnose Point, some miles to the north of Bude. 

 The bed in question varied from 21 to 24 inches in thickness, and 

 the weathered surface closely resembled that of the bands occurring 

 near Westward Ho ! 



A calcareous spring was also observed about 2 miles south of 

 Bude, and north of Phillip's Strand. It issues from the face of the 

 cliff, some 15 to 20 feet above the shore-line, and deposits masses 

 of tufa, several inches thick. Obviously, calcareous rocks, although 

 not observed in the coast-section, must occur not far distant from 

 this spot. McMahon, 1 however, failed to find any evidence of such 

 rocks near Bude. 



The composition of these rocks varies considerably, as to the 

 amount of lime present ; but in all the cases tested they w^ere 

 found to effervesce briskly with an acid. Mr. Howe has very 

 kindly made a preliminary examination of several specimens for me. 



An example of one of the many bands in the Cornborough 

 Cliffs was pronounced to be an impure limestone. Mr. Howe says 

 that, in section, it appears as a very fine-grained, brownish, opaque 

 rock with a microscopic mottling due to incipient crystallization of 

 a yellow-stained carbonate. Minute fragments of vegetable tissue, 

 pyrites-specks, and quartz-grains are also present. 



Another, from a thick band in an anticline in the Abbotsham 

 Cliffs, is described as a fine-grained, even-textured sandstone with 

 a muddy calcareous cement. 



A specimen, typical of one of the smaller bands, is defined as a 

 sandy, calcareous mudstone, in which the sand-grains are exceed- 

 ingly fine but fairly abundant, and the calcareous cement subordinate 

 and local. Parts of the rock do not effervesce with acid. Another, 

 from Abbotsham Cliff, is a fine-grained, muddy, and calcareous 

 sandstone, similar to the last but rather coarser, and more sandy. 

 Fragments of plant-impressions occur in it. The last specimen, 

 also from Abbotsham Cliff, is termed by Mr. Howe a muddy 

 limestone. 



The only fossils that have been found in these limestone-bands 

 are fairly well-preserved pith -casts of Catamites Suckoivi, Brongn., 

 and fragments of fronds of Alethopteris lonchitica (Schl.), of which 

 several examples have been collected. No goniatites have ever 

 been obtained from them. The original rocks, now converted into 



1 McMahon (90) p. 109. 



