GENUS GLOBIGERINA. 183 



remain in continuity with that from which they are put forth (as they do in exceptional cases), 

 we should have the likeness of GloUgerina, differing solely in the presence of the large pores 

 which constitute the distinctive feature of Orbidina. Again, the wildly growing forms o) 

 GloUgerina obviously tend towards Carpenlerin, as will be evident when the remarkable struc- 

 ture of that genus shall have been explained. By its symmetrical variety, Glohigenna is showoi 

 to be related to those nautiloid Foraminifera which are the highest types of the hyaline series. 

 But its nearest relationships are to its congeners Pullenia and SpJueroidina, and to the Rota- 

 line genera Discorbina and Planorhnlina ; the smooth-walled compact GloUgerina (such as 

 have been named G. ittflata by D'Orbigny, v) presenting a close approximation to specimens 

 of Pidlenia obliquiloculata of Parker and Rupert Jones (a variety of the Nonionina sphmroides 

 of D'Orbigny) brought up from great depths ; the large, extremely thick-walled, compact 

 GloUgerina of the deepest waters approaching in like manner to the equally abyssal solid 

 Sphceroidiria ; and the moderately depressed flat-chambered forms presenting a strong 

 resemblance to certain modifications of the Rotaline type. 



297. Geographical Distribution. — -This genus ordinarily inhabits the deeper waters of tlie 

 ocean, through which it is very extensively distributed, although not as universally as has 

 been represented. It is not common in shore-sands or in dredgings from shallow waters ; but 

 often presents itself in extraordinary abundance in deep-sea dredgings, and in the contents of the 

 scoop attached to the deep-sea sounding-apparatus. Thus Mr. Parker found it to consti- 

 tute 97 per cent, of the soundings brought up by Capt. Dayman from a depth of 2000 fathoms 

 in the Mid-Atlantic ; and Dr. Wallich (civ a) met with a like proportion in soundings taken 

 between Cape Farewell (Greenland) and the island of Rockall, at depths respectively of 1260 

 and 1607 fathoms. The surface-layer of the "ooze" seems to be formed of living shells; 

 whilst its principal mass consists of the exiivicB of preceding generations. It is a remarkable 

 fact that the occurrence of GloUgerinm in any quantity in the deep-sea deposits of the 

 Northern Atlantic Ocean is associated in an intimate manner M'ith the presence of the Gulf 

 Stream or its offshoots. Thus they abound in the soundings taken between Ireland and 

 Newfoundland, in those taken between the Faroe Islands and Iceland, and in those taken 

 midchannel between Iceland and Greenland, — diminishing, however, towards the latter 

 coast ; whilst from the soundings taken between Greenland and Labrador they are entirely 

 absent. Again, they have been found in the deep waters off Shetland more abundantly than 

 in the neighbourhood of any other portion of the coast of Great Britain ; and thej' a-re also 

 met with on the northern coast of Norway. This association appears to be wholly irrespective 

 of the direct drifting action of the Gulf Stream, which can scarcely extend to the profounder 

 depths of the ocean ; and it would rather seem to depend on the presence in it of a large 

 quantity of organic particles, derived from the Gulfs of Mexico and Florida, or from the 

 Sargasso fields, which afford nutriment to the Globigerince. The genus is also met with, 

 frequently in such abundance as to constitute 50 per cent, of the " ooze," in the deeper 

 waters of the Mediterranean and the Adriatic, in the Red Sea, and in the neighbourhood 

 of the Canaries, the West Indian Islands, the eastern and western coasts of South America, 

 St. Helena, and the Isle of France. On the other hand, in the deep sea-soundings taken 

 in various parts of the great " Coral Sea," Glohigerina do not seem to occur. 



298. Geological Distribution. — As far as is yet known, this genus first presents itself in 



