292 A. J. JUKES-BROWNE ON THE RELATIONS OF 



NATICA GAULTINA, D'Orb. 



Natica gaultina, D'Orb. Pal. Fr. p. 156, pi. 173. f. 3 & 4; Pictet 

 & Eoux, Gres Yerts, pi. 18. f. 1. 



Natica truncata, Gres Yerts, pi. 18. f. 2. 



N. canaliculata, Sow. Geol. Trans, iv. pi. xi. f. 12. 



This species is by no means common near Cambridge, though 

 many individuals have been found, and three fine specimens are in 

 the possession of Mr. A. F. Buxton, of Trinity College. At Folke- 

 stone it is common both in Lower and Upper Gault. It is certainly 

 the N. canaliculata of Sowerby ; and I agree with M. Eenevier in 

 seeing little difference between it and the N. truncata of Pictet and 

 Eoux. The obliquely elongated body-whorl characterizes both, as 

 well as the depression of the upper whorls. 



Natica Eatjliniana ?, D'Orb. 



Natica Bauliniana 1 ?, D'Orb. Pal. Fr. p. 160, pi. 174. f. 4; Pict. 

 & Eoux, Gres Yerts, p. 183, pi. 18. f. 2. 



Another Natica of about the same size as N. gaultina, but more 

 compact and globose in shape, and with a more elevated spire, also 

 occurs in the Cambridge deposit. Mr. Seeley has referred it to N. 

 Matheroniana, D'Orb. ; but I cannot observe much likeness between 

 D'Orbigny's figure and the specimens in the Woodwardian Museum. 



It comes nearer to N. Mauliniana, D'Orb. ; but even this is rather 

 more elongated than our casts, which not improbably belong to an 

 undescribed species. Until comparison with foreign specimens shall 

 enable me to decide upon this point, I have thought it best to retain 

 the Cambridge casts under N. Bauliniana, to which they certainly 

 bear considerable resemblance (see D'Orbigny, ii. p. 160). 



Littorina (?) crebricostata, Seeley. PI. XIY. figs. 10, 11. 



This pretty little shell is so named in the "Woodwardian Museum ; 

 but I am not aware that Mr. Seeley has ever described or figured it. 



The cast is of an elongated turbinoid shape, consisting of five 

 rounded whorls ornamented with faint ribs, thickly set and most 

 strongly marked on the upper part of each whorl ; the section of the 

 whorl is nearly round. In height it averages 6 lines ; and the base 

 measures § of an inch. It is more like Trochus than Littorina \ but 

 I adopt Mr. Seeley 's name. 



Trochus Tollotianus, Pict. & Eoux. PL XIY. figs. 7-9. 



Trochus Tollotianus, Pict. & Eoux, Gres Yerts, p. 203, pi. 19. f. 9; 

 Pict. & Camp. Ste. -Croix, ii. p. 529. 



? T. cancellatus (partim), Seeley, Ann. & Mag. Nat. Hist. 1861, 

 vol. vii. pi. xi. p. 15. 



Pictet and Campiche speak of casts from Cambridge similar to 

 their specimens of this shell ; I can only suppose these to be one of 

 the forms of Trochus cancellatus, Seeley, which vary rather in shape 

 and amount of angulation. Neither MM. Pictet and Eoux's figure, 

 nor those of Mr. Seeley are very good ; and I have therefore thought 



