Manchester Memoirs, Vol. Ixii. (191 7) jj 



166. Nodosaria raphanus (Linne). 



Nautilus rap hanus, Linne, 1758, Syst. Nat. ed. 10, p. 711. 

 Nodosaria raphanus, Brady, 1884, Chall. Rep., p. 512, 

 pi. LXIV, figs. 6-10. 



Not rare. The specimens are long and slender with well- 

 marked costae, which are not always parallel with the axis of 

 the shell but occasionally obliquely disposed. This feature, to- 

 gether with the fact that there is also sometimes a slight 

 •curvature of the shell, shows a distinct relationship with Denta- 

 iina obliquata (Batsch). In the latter species, however, the 

 costae are not prominent or trenchant. 



167. Nodosaria (Dentalina) acute-costata, Silvestri. 



Nodosaria acute-costata, Silvestri, 1872, Atti Accad. Gioenia. 

 Sci. Nat., s. 3, vol. VII, p. 48, pi. IV, figs. 82-89. 



This variety of N. raphanus has the commencement of 

 the shell pointed and sometimes hooked, that is to say, it be- 

 gins with rather a sharp curvature which becomes flatter as 

 additional segments are added, and may become perfectly 

 straight. The costse are few and strong, and generally oblique 

 on the earlier portion of the test. 



(The species cannot be usefully separated from N. 

 raphanus.) 



168. Nodosaria raphanistrum (Linne). 

 PI. IV, fig. 4. 



Nautilus raphanistrum, Linne, 1758, Syst. Nat., ed. 10, p. 710; 



1788, ed. 13 (Gmelin's), p. 3,372. 

 Nodosaria raphanistrum, Jones, Parker, and Brady, 1866, 

 Crag. Foram., Palseont. Soc, vol. XIX, p. 50, pi. I, figs. 6-8. 



This species is frequent in the Marls of Biarritz, but owing 

 to their length the specimens are not often found unbroken. 

 The forms known as Nodosaria affinis, d'Orb., and N . bacil- 

 lum, Defr. are both found; the latter attaining the greatest 

 dimensions, two examples each measure nearly fin. in length, 

 whilst the other form only reach half that length. 



I have thought fit to give a figure of a transverse section 

 of a specimen in order to show the constitution of the shell wall. 

 It will be seen that the costse are wedge-shaped in section and 

 are composed of compact imperforate substance, and that the 

 shell-wall proper, between the costae, is composed of several 



