Nomenclature of the Foraminifera. 345 



Clay. In the latter this form is abundant. It is the Nodosaria 

 obliqua, Linn, sp., as Montagu thought. D'Orbigny's Dentalina 

 acuta is an analogous variety. 



(D. c.) PI. 14. f. 5, p. 199. " Nautilus costatus." The figure 

 shows a straight and few-ribbed variety of Xodosaria Raphanus. 

 This also is most probably fossil. 



(D. d.) Supplem. pi. 19. f. 2, p. 83. " Nautilus costatus, var." 

 A fragment of a straight symmetrical Nodosaria. In describing 

 this variety, Montagu correctly remarks that this form is "sub- 

 ject to very great variation." Probably fossil. 



(D. e.) PI. 14. f. 1, p. 525. " Vermiculum Urnae." " Found in 

 sand from Sheppey." Probably the first cell of a Nodosaria 

 (from the London Clay of Sheppey), showing the fractured wall 

 of the next or second cell, encircling the base of the conically- 

 produced septal face. The opposite, or lower, projecting point 

 is the usual terminal pricklet. 



(D./.) PI. 6. f. 5, p. 198. "N. subarcuatus." One of the 

 innumerable Dentaline modifications of Nodosaria. Montagu 

 mentions having seen a drawing of another variety. Both were 

 from Sandwich. The " brown epidermis" may probably have 

 been due to fossilization. 



Several varieties of these delicate tapering shells abound in 

 the Tertiary clays (the cliff-washings of which afforded Boys and 

 "Walker so many Foraminifera) ; and some occur recent on our 

 coasts, though they are neither large nor plentiful. In the 

 Mediterranean and elsewhere they abound on deep mud bot- 

 toms. Authors have noticed and figured hundreds of the varie- 

 ties, recent and fossil, as distinct species. D'Orbigny's Dentalina 

 communis (from the Adriatic, and fossil in the Chalk) has the 

 chambers oblique and distinct, and is a good sub-type ; but 

 Lamarck's older name, Nodosaria dentalina (An. s. Vert. vii. 

 p. 596, no. 2) is well adapted for this group. Montagu's spe- 

 cimen, above referred to, has the septal lines of its earlier seg- 

 ments unmarked, and the later chambers are globose. 



Prof. Williamson has taken Montagu's "N. subarcuatus" as 

 the type of the Dentaline group. In this we cannot agree; for 

 we do not regard this shell as a good typical form. The well- 

 grown specimens of Dentalina communis (N dentalina) of the 

 Adriatic and Mediterranean far better represent the characters of 

 the slender tapering arcuate Nodosaria 1 furthest removed from 

 N. Raphanus. 



(D.g.) P. 197, and Supplem. pi. 19. f. 4 & 7, p. 82. "Nau- 

 tilus rectus." At p. 197, N. Legumen is described under this 

 name : but in the " Supplement" these forms are separately and 

 correctly defined. Montagu's N. rectus is a thickish and nearly 

 straight form of Nodosaria dentalina, very common in the Lon- 



