212 FORAMINIFERA OF THE CRAG. 



Characters. — Our small specimen from the Crag consists of four short, almost 

 equal chambers, broader than long, closely set one on another. Zoologically it is 

 a variety of N. radicula (Linne) ; it has many slight modifications of shape, and 

 is closely allied to other forms belonging to the same group. 



Among the figured forms we find that figs. 9 and 10 of E. Dervieux's pi. v 

 are also referred to ambigua at p. 625. Nodosaria De-Amicis, Derv., on the same 

 plate, figs. 63, 63 bis, though larger, papillose, and mouth-tubed, is specifically 

 the same. 



In the numerous figures given by Soldani, rough as they are, much of interest 

 is shown among the many varieties of iV^. radicula of this sub-type " ambigua." 

 In the fig. L (pi. vi) referred to above, after the large ovoid primordial segment, 

 the four succeeding chambers are short, equal, and closely set. The fig. zz 

 (pi. cii) has also a large primordial segment ; the later chambers are shorter than 

 broad as in ambigua, but are irregular in size and direction of growth. Fig. a 

 (pi. cii) has very short and closely-set chambers ; it is much larger than fig. l 

 (pi. vi), and somewhat sinuous in its line of growth. Figs, p, g, h (pi. ciii), also 

 have short close-set chambers ; and fig. k combines this feature with that of 

 an obliquely striated Dentalina, having put on the chambers of the radicula type 

 in later life. 



The individual, fig. 4c {Nodosaria radicula, parte), in pi. ii, of G. Terrigi's 

 memoir in the ' Mem. Descr. Cart. geol. d' Italia,' vol. iv, part i, 1891, is the same 

 as JV". ambigua. 



Occurrence. — This variety of N. radicida lives in the Mediterranean (Soldani), 

 and at 129 fathoms off" the Ki Islands ('Challenger'), It occurs fossil, with 

 other Nodosarige, in several Tertiary formations. 



The typical N. radicula has a wide geographical range, but it has been most 

 frequently recorded from high latitudes, at depths ranging from 10 to 300 fathoms. 

 Specimens have also been obtained from the North and South Atlantic (1360 and 

 2350 fathoms), from the South Pacific (37 to 1100 fathoms), from off the Cape of 

 Good Hope (150 fathoms), and from the Adriatic. 



Its geological range extends back to the Permian of England and Germany. 

 It has also been met with in the Lias of England, in the Kimmeridge Clay, in the 

 Gault of Folkestone, in the Red Chalk of Speeton, in the Upper Chalk of Taplow, 

 Bucks, and of Keady Hill, Ireland ; in the London Clay (Eocene) ; in the Miocene 

 of Italy, Vienna, and Malaga ; and in the Pliocene of Italy, Garrucha (South 

 Spain), and St. Erth. In the Coralline Crag it has been found at Sutton ; and at 

 Sudbourne, zone d. 



