180 DREDGINGS OF THE MARINE BIOLOGICAL ASSOCIATION : 



H. 19. Broken off by trawl about 20 miles S.AV. of Eddystone. 



Granite of coarse grain. Both white and black micas present. A little triclinic 

 felspar in addition to the orthoclase. The quartz contains large fluid inclusions 

 with bubbles. Apatite is abundant in rather large crystals. — E. B. T. 



H. 20. About 10 miles S.W. by S. of Start Point, weight about 15 to 

 16 cwt. 



A coarse grey granite with silvery mica in addition to dark mica. Felspar 

 chiefly orthoclase, but a little triclinic felsj^ar, including microcline, is present. 

 The quartz contains fluid cavities. An occasional tendency to micropegniatic 

 structure. — E. B. T. 



H. 27. Trawled 18 miles S.W. of the Start. 



A rather fine-grained granite, reminding Prof. Bonney somewhat of granites 

 from one or two localities in the Channel Isles. 



It consists of quartz, felspar (orthoclase, oligoclase (1), and perhaps 

 microcline), and two micas, black and white, the former occasionally some- 

 .what altered. — T. G. B. 



H. 34. Trawled 18 to 20 miles S.S.W. of Start Point. Weight 9 or 

 10 cwt. 



A true granite, a good deal decomposed. — T. G. B. 



H. 35. Trawled 21 miles S.W. of Start Point. Weight about 5 cwt. 

 A granite containing quartz, with the usual felspars, hornblende, and brown 

 mica. — T. G. B. 



H. 39. Trawled 15 miles S.E. by E. of Berry Head. Weight 4 to 5 cwt. 



A rather fine-grained granite of a warm greyish colour. It consists of quartz, 

 — containing fluid cavities, with bubbles and some acicular microliths (^rutile) 

 — felspar, somewhat decomposed, both orthoclase and plagioclase (? oligoclase), 

 brown mica, occasionally somewhat decomposed, a little white mica, and iron 

 oxide.— T. G. B. 



H. 42. Trawled 12 miles S.W. of Start Point. Weight 3 cwt. 



A moderately finely crystalline rock, speckled lighter and darker grey, 

 looking like a granite, with possibly a slight foliation. Consists of quartz, 

 felspar (orthoclase and plagioclase), and a considerable quantity of brown 

 mica, Avith a rich colour and strong dichroism. Now and then there is a little 

 white mica. — T. G. B. 



Four Hornblbndic Granite. Nos. 4, 21, 24, 25. 



H. 4. Trawled 15 miles S.W. of Start Point. A rounded block measuring 

 3' 6" X 2' 3" X r 8". 



A coarse-grained rock, exhibiting colourless felspar and quartz, black horn- 

 blende, and brown mica. Hornblende and biotite abundantly present. Of 

 the felspars, orthoclase and plagioclase seem in almost equal proportions ; both 

 are much decomposed and kaolinised in i:>atches. The quartz contains a 

 quantity of hair-like crystals of undetermined nature ; besides these are a 



