108 FORAMTNIFERA OF THE CRAG. 



3. Spirolocttlina canaligulata, d'Orbigny, 1846. Plate III, figs. 39,40 ; Woodcuts, 



figs. 3 a, 3 b 

 Part I, I860, page 10 ; and Appendix II, 

 Table, No. 16. 



Spiroloculina cymbium, d'Orb., 1839. Hist. Nat. Canaries, p. 140, pi. iii, 



tigs. 5, 6. 

 canaliculata, d'Orb., 1846. Foram. Foss. Vienne, p. 269, pi. xvi, 



figs. 10—12. 

 Costa, 1856. Atti Accad. Pontan., vol. vii, fasc. 2, 

 p. 312, pi. xxiv, fig. 10. 

 — var., Costa, 1856. Ibid., fig. 9. 



Jones, Parker, and Brady, 1866. Monogr. Foram. Crag, p. 16, 



pi. iii, figs. 39, 40. 

 depeessa, Terquem, 1878. Mem. Soc. Geol. France, ser. 3, vol. i, 



p. 54, pi. x, fig. 11. 

 canaliculata, Terquem, 1881. Plage Dunkerque, fasc. 3, p. 133, 



pi. xvii, fig. 12. 

 limbata, var., Brady, 1884. Report ' Challenger,' p. 150, pi. x, 



figs. 1, 2. 

 planulata, Brady, Parker, and Jones, 1888. Trans. Zool. Soc, 



vol. xii, p. 214, pi. xl, figs. 14, 15. 

 canaliculata, Egf/er, 1893. Abhandl. k. Bayer. Akad. Wiss., 



cl. ii,vol. xviii, pp. 218, 224, pi. i, 

 figs. 40, 41. 

 impress.*, Eager, 1893. Ibid., figs. 35, 36. 



ef'r. bicarinata, d'Orb., 1 ScJtivager, 1883. Palasonto- 

 grapbica, vol. xxx, p. 85, pi. xxiv, 

 fig. 4. 

 dkpkessa, d'Orbigny 

 PERFORATA, d'Orbigny 

 Gbateloupi , d' Orbigny 

 bicarinata, d'Orbigny 



For notes on these forms see p. 35. 



Characters. — Lateral surfaces of the chambers plane, with or without limbate 

 sutures; the peripheral margin channelled; centre usually somewhat concave. 



The gradational differences of the test, due to greater or less amount of 

 shell-growth along the edges of the chambers, give rise to some confusion in the 

 classification of the noticeable varieties. If the exogenous or extra shell-growth 

 predominates on the edges of the periphery, it makes a channel along the outer 

 margin. This feature characterises d'Orbigny's well-shaped Spiroloculina canali- 



1 As defined by Terquem, ' Mem. Soc. Geol. Fr.,' ser. 3, vol. ii, 1882, p. 155, pi. xxiv, fig. 5. 



