LIMA. 15 



inverted W. The ribs are slightly raised and often somewhat wavy or irregular, 

 especially near the growth-ridges. The ribs and grooves are crossed by numerous 

 concentric linear ridges. The ribs are sometimes nodular, the nodules having a 

 concentric arrangement. At intervals, usually rather distant and fairly regular, 

 distinct growth-lamellae are seen. 

 Measurements : 



(i) (2) (3) 



Length . 37 . 20 . 22 mm. 



Height . 51 37 . 32 „ 



(1) Chalk, Newtimber. 



(2) B. mucronata zone, Norwich. 



(3) H. planus zone, Dover. 



Affinities. — See L. (Ctenoides) rapa (p. 42) and L. {Ctenoid es) tecta (p. 43). 

 L. divaricata also presents some resemblance to Lima Holzapfeli, Hennig, 1 found 

 in the Danian of Faxe. 



Remarks. — This species has hitherto been known in England as Lima granosa, 

 Sowerby. After making a careful comparison I feel no hesitation in regarding 

 it as identical with the widely-distributed Ij. divaricata, Dujardin. This form is 

 comparatively rare in England, and the part of the shell near the umbo is usually 

 wanting or imperfectly preserved. 



Type. — From the Chalk (? Lower Senonian) of Touraine. Sowerby does not 

 mention the locality or the horizon from which he obtained Lima granosa, and I have 

 not succeeded in finding the type. 



Distribution. — Zone of Terebratulina of Hitchin. Zone of Holaster planus of 

 Winchester, Dover, and Cheveley, Blue Bell Hill, Burham (P H. planus zone). 

 Chalk Rock of Cuckhamsley. Zone of Micraster cor-anguinum of Micheldever. 

 Zone of Actinocamax quadratics of Salisbury. Zone of Belemnitella mucronata of 

 Salisbury and Norwich. 



Sub-genus — Limatula, 8. V. Wood, 1839. 



(' Mag. Nat. Hist.,' new series, vol. iii, p. 233.) 



Lima (Limatula) Tombecktana, d'Orbigny, 1847. Plate VII, figs. 7a, b, 8 a — c, 9a, b. 



1847. Lima Tombeckiana, A. d'Orbigny. Pal. Franc. Terr. Oct., vol. iii, p. 534, 



pi. ccccxv, figs. 13 — 17. 

 1850. d'Orbigny. Prodr. de Pal, vol. ii, p. 82. 



1 'Bih. E. Svenska Vet. Akad. Handl.,' vol. xxiv, No. 7 (1899), p. 10, pi. i, figs. 1, 2; Kavn, 

 ' Mollusk. Danmarks Kridtafl I. Lamellibr. ' (1902), p. 100, pi. ii, fig. 15. 



