354 ADDENDA. 



will confirm in every respect the results of tlie previous soundings 

 made in about the same regions. There is evidently a drift from 

 the north of coarse mineral matter, which is deposited in the neigh- 

 borhood of the Banks ; but all the rest of the way clear across, 

 and approaching pretty closely to the British shore, the whole bot- 

 tom is a fine calcareous mud, containing no particles of mineral 

 matter as large as a mustard-seed, and, in fact, almost wholly 

 made up of perfect shells of Foraminifera, a fine mud produced by 

 their decay, and a smaller portion of silicious organisms, such as 

 Diatoms, Polycistias, sponge spicales, etc. 



"From. the results of three slides which I mounted to-day, I 

 expect to find almost a perfect correspondence of the species to 

 those already noticed in the deep soundings of the Atlantic. I 

 have noticed no new species as yet, but have scarcely glanced at 

 the slides. 



"The specimens I mounted to-day were No. 20, lat. 52° 01^, 

 long. 17° 06^ in its natural state ; No. 20, lat. 52° OV, long. 17° 

 06^, acted upon by chlorohydric acid; No. 11, lat. 51° 15^, long. 

 34° 08^, in its natural state. 



" The specimens in natural state gave great numbers of micro- 

 scopic Foraminifera (with an occasional granule of quartz, etc., of 

 microscopic minuteness), and here and there a Diatom or Polycis- 

 tia could be seen. 



"In the specimen cleaned by acid, the calcareous mud being 

 dissolved out, the silicious particles were left, and among these an 

 abundance of Diatoms, Polycistias, and Sj)ongiolites were found. 



" I have no doubt our beautiful ' ocean river' glides along its 

 course in the Northern Atlantic as gently as the current of time, 

 dropping now and then a defunct animalcule into the great sepul- 

 chre below, but not wearing or abrading the bottom in the slight- 

 est degree." 



A week after he again writes : 



" Well, I have something new that will set you thinking. I 

 have been, digging away in the muds, getting deeper and deeper 

 from No. 1 (lat. 47° 50^ long. 52°) to No. 15 (lat. 52° 26', long. 

 26° 20^) and 16 (lat. 52° 2', long. 24° 51^, finding the calcare- 

 ous organisms increasing in number as I got east, when, all of a 



