394 J. F. BLAKE AND W. H. HTJDLESTON ON 



Cebtthitjm inoenatum, Buvignier, Geol. de la Meuse, pi. xxvii. 

 fig. 17. 



Unornamented Cerithia, to which the above-quoted figure bears 

 the closest resemblance, are not uncommon in the Rag-beds of 

 Brompton and Ayton. A similar shell, however, from the Trigonia- 

 beds of Pickering, shows, under a strong lens, excessively fine longi- 

 tudinal striae ; and we are not sure whether this may not be the 

 Terebra melanoides of Phillips, which otherwise we have not met 

 with. A block of Rag from Ayton is figured (PL XIV. fig. 1), showing 

 this and three other species. 



Cekithitjm, sp. (cf. viEDUNENSE, Buvignier). PI. XIY. fig. 2. 



A small shell from a bed full of micromorphs at Cauklass End, in 

 the vale of Pickering, agrees well in other respects with Buvignier's 

 species, but that it is only one sixth the size. As, however, its 

 identity may be doubtful, we give a figure. If considered distinct, 

 it may be called Oerithium gradatum. 



Neein^ea fusifoemis, D'Orbigny. PI. XIY. figs. 3, 3 a. 



Notwithstanding that this species is well figured in D'Orbigny's 

 Pal. Prang. Terr. Jurassiques, we give a figure of it, because it is so 

 important and characteristic a shell in the Rag of the Scarborough 

 district. 



Natica maechamensis, spec. nov. PI. XIY. fig. 4. 



Naticce, as a rule, present few characters ; and one usually feels an 

 embarras de richesses when names have to be invented for them. 

 Two, however, we cannot match elsewhere ; and they are marked 

 with extreme characters in opposite directions. 



JV. marchamensis is uniformly convex, the convexities of each 

 whorl almost joining, to make but one curve, the sutures being very 

 feebly marked. Spiral angle 66°. Last whorl more than -| the 

 whole. 



In the Natica-hed of Marcham and the neighbourhood. 



Natica felina, spec. nov. PL XIY. fig. 5. 



This is as remarkable for the step-like character of its spire, the 

 top of each whorl being perfectly horizontal, and separated angu- 

 larly from the sides. It was ornamented with three dark-coloured 

 longitudinal bands. Spiral angle, which is increased by the last 

 whorl, 85°. Last whorl f the whole. 



In the Lower Calcareous Grit, Catcombe, Wiltshire. 



Neepiopsis. PL XIY. fig. 6. 



Fossils like the one figured were for a long time a puzzle, ana 

 were commonly referred to some Cephalopod, like Beloptera, under 

 the name of Peltarion, till they were discovered by M. Beaudouin 

 (Bull. Soc. Geol. de France, vol. xxvi. 2nd series, p. 182) in their 

 natural position as an operculum of a Neriiopsis. This particular 



