cl GENERAL SUMMARY OF SCIENTIFIC AND 



tensive belts of these organisms are still living at great 

 depths, and serving the purpose, precisely after the manner 

 of land plants, of eliminating carbonic acid, appropriating 

 the carbon and giving forth the oxygen. 



One of the finest yields of diatomacea), principally Coscino- 

 discus omphalanthas, C. concavus, Asterolampra BrooJcei, 

 Mhizosolenia hebetata, and Triceratrwn arcticiwi, was from 

 latitude 52 11' north and longitude 1*76 48' east, from a 

 depth of 1681 fathoms. Another cast, latitude 43 47' north, 

 longitude 150 2' east, from a depth of 4234 fathoms, con- 

 sisted almost entirely of diatornaceae, principally Coscinodis- 

 cus and Biddulphia. 



Anions other interesting results from examination of the 

 deep-sea soundings of the Tascarora, we may mention the 

 occurrence of undoubted living foraminifera, not derived 

 surface forms, at a depth of 2711 fathoms. At this depth, as 

 might be expected from the large amount of carbonic acid, 

 no calcareous organisms could exist, and none, except a stray 

 globigerinciy too recently dropped to be dissolved, were found; 

 but there were multitudes of sandy Lagenidce, some very 

 large ; also Litaoldice (especially L. ccmariensis, and various 

 Trochammince and Dentalince, with polished sandy tests like 

 Trochammind). But the most noteworthy fact was the oc- 

 currence of Orbulma, not with calcareous or sand-incrusted 

 calcareous tests, but with shells wholly of sand grains, and 

 perfect in shape, too large and heavy to have ever floated. 

 The abundance and character of all these forms, along with 

 which were numerous sand tubes and great numbers ofAcan- 

 thomet?'i>ice, TkaUassicoUince, and Polycystince, preclude the 

 idea of dropped surface forms. In another sounding, of 108 

 fathoms, were fine specimens of Idngulina, and some trans- 

 parent enough to show distinctly the early growth, a rapidly 

 increasing spiral, which is masked entirely in the fully devel- 

 oped, and more or less sandy rectilineal tests of the matured 

 form. At a depth of 1625 fathoms, specimens were found of 

 the genus Ellipsoidina of Professor Seguenza, hitherto only 

 known as fossil from the miocene marls around Messina. 



In a paper read before the Royal Society, November 26, 

 1874, by Professor C. Wyville Thompson, the origin of the 

 calcareous formation known as " globigerina ooze " is attrib- 

 uted to surface organisms, as advocated bv the late Professor 



T* / m* 



