On Microzoa, &c. By C. D. Sherbom & F. Chapman. 751 



spines to triangular points (as in Sowerby's figure, which is a 

 typical condition), from points to winged terminal riblets at the 

 bases of the chambers, and further to riblets often continuous along 

 the first-formed portions of the shell. The same gradations are 

 shown, though less perfectly (on account of the paucity of indi- 

 viduals) on tablet 49,491, in the British Museum (Nat. Hist.). 

 This series came from the London Clay of Haverstock Hill, London. 

 Montagu's original figure appears to represent some of the middle 

 chambers of a D. adolpliina d'Orb. A reference to our figure of 

 this variety (fig. 11a) will show that the uppermost chambers 

 become elongate sometimes and fully spinose as in some chambers 

 of D. spinulosa. Very common in both clays, generally 

 fragmentary ; also at Chelsea. FlG - 154 - 



Dentalina acicula (Lamarck). Woodcut, fig. 154. 

 Orthocera acicula Lamarck, 1822, Hist. Anim. sans 

 Vert., vii. p. 594, No. 5.— Here are some lower cham- 

 bers of an individual belonging to this variety. There 

 is a similar fragment in the British Museum, tablet 

 49,490) from the London Clay, Islington, London), 

 which shows the same continuous costse. In both cases 

 the upper part has disappeared. This form commences 

 from a point and increases gradually in size. 



Lamarck says it is straight {Nodosaria), but the 

 difference between Nodosaria and Dentalina being merely one of 

 curvature, we refer it to this latter form, taking as our type the 

 specimen quoted above, from the British Museum, and included in 

 Prof. Bupert Jones' Catalogue, p. 20. Black clay. 



Dentalina muUilineata Bornemann, plate XV. fig. 14. Borne- 

 mann, 1855, Zeitschr. d. geol. Ges., vii. p. 325, plate xiii. fig. 12. — 

 A curved, horizontally chambered, and finely ribbed form, of which, 

 unfortunately, the top is missing. Although Bornemann's figure 

 only gives us three chambers, still, considering its fine ribbing and 

 the position of chambers, we consider our form to be the same. In 

 1874 Eeuss figured in Geinitz's ' Elbthalgebirge,' 4to, Cassel, 

 1872-4, plate xx. fig. 13, the upper end of a Dentalina, the same 

 as that of Bornemann, calling it a new species and using the same 

 name as Bornemann did twenty years before. Two fragments; 

 black clay. 



Dentalina obliquestriata Eeuss, plate XV. fig. 15. Eeuss, 

 1851, Zeitschr. d. geol. Ges., iii. p. 63, plate hi. figs. 12, 13. — 

 Under this name Eeuss figures in his ' Septarienthon,' two lower 

 ends of a Dentaline form, with fine oblique striae. Batsch, in 

 1791, figured a form very similar, but with fewer, coarser, and 

 more continuous costae; and this he called Nautilus obliquatus. 

 Our specimen consists of five chambers, and both ends appear to 

 have been broken away. One specimen ; black clay. 



