314 MR. S. N. WOETH ON A SIJBMAEINE TEIASSIC 



COD taming both black and white micas, the former rather 

 segregative. 



4. Falmouth Castle ,18 miles N.N.W. — Fine-grained, compact, 

 red, jaspideous sandstone, much bored, possibly an altered rock. 

 The specimen shows portions of two joint-faces, at right angles to 

 each other, which have evidently been protected from the ravages 

 of the Pholades. 



5. Deadman, 25 miles N.E. by N. — This one spot supplied 

 examples of four distinct Triassic rock-forms : — 



a. Chocolate marl, spotted white. The edges of this nodule were 

 rounded, but it could hardly be called rolled. From its softness 

 this is very easily worn. 



b. A " Potato Stone," partially coated with marl, and filled with 

 pinkish calcite. The inside of the shell was studded with small 

 brilliant pyramids of quartz. Five inches in longest external 

 diameter. 



€. Grey sandstone. 



d, A nodule of Triassic trap, which may have been partially 

 rolled, but was apparently in its form originally concretionary. It 

 is a hard red rock of meagre feel, slightly micaceous, and very 

 closely resembles some varieties of the Triassic trap of Thorverton, 

 with affinities, so far as macroscopic observation goes, to those of 

 Pocombe and Cawsand. 



6. Deadman, 20 miles N. by E. — A light salmon-tinted drab cal- 

 careous sandstone, in a slab nearly two feet in longest diameter, the 

 under surface intact and slightly pitted. This is the only example 

 of the series that I am unable to match distinctly among the Eed 

 Rocks of Devon ; but its associations here are apparently Triassic, 

 and I therefore include it in my notes. Probably it may be identified 

 by those more familiar with Triassic detail than myself ; though, 

 indeed, it may not be Triassic at all. 



It will be seen that the affinities of this series are with the 

 Keuper of Devon, and particularly with the rocks in the vicinity of 

 Sidmouth. 



A comparison of the bearings given will show that the rocks from 

 which these specimens were derived lie to the S.E. of the Lizard 

 promontory, occupying an area of which the centre may approxi- 

 mately be given, on the data to hand, as about 10 miles S.E. of the 

 Lizard Head, and most of which lies beyond the 40-fathom line, and 

 all beyond the 30-fathom. Of course with the information at present 

 existing no attempt can be made to map out the boundary of this 

 submarine Triassic outlier ; but there is some evidence that it does 

 not extend to the eastward, approximately, beyond the meridian of 

 the Nare Head, in the fact that rocks brought up from the following 

 positions do not include any of Triassic character : — Deadman, 3 

 miles N.W. ; Deadman, 4 miles E. ; Deadman, N.E. 10 and 12 

 miles ; Deadman, 27 miles JST. by W. ; while the position which 

 yielded the calcareous sandstone (ISTo. 6) has produced pebbles of 

 granitic, granitoid, and quartzite rocks, with flints, with no distinct 

 example of Trias. So far as Falmouth Eay is concerned, we have 



