W. H. Hudledon — On the YorLshire Oolites. 57 



would scarcely help us out of our difficulty here. We might agree 

 to call all specimens with straight longitudinals and a flat whorl C. 

 Culleni; and those with curved longitudinals and more tumid whorl 

 C muricatum, without reference to the number of spirals. Or, if we 

 try another method, we might call the specimens with rounded nodes 

 C. grcmulato-costatum, and those specimens with spinous nodes G. 

 muricato-costatum. Thirdly, if we adopted the number of spirals as 

 our test, we should have (7. sexUneatum (Fig. 3), G. quiiiquelineatum 

 (Fig. 2), C. quadrilineatim (Figs. 1 and 5), C. trilineatum (Fig. G). 

 Eonghly speaking, two sections of the group seem to declare them- 

 selves, and under these most of the forms might be arranged, though 

 such an arrangement would only be of an incomplete and partial 

 character. The first section would be arranged under C muricatum, 

 Sow., with its curved longitudinals, and its whorls somewhat tumid 

 though flattened in the centre and rather constricted towards the 

 base, it has usually 5 spirals. Very fine specimens of this type 

 occur in the Dogger Sands, more rarely in the Dogger, and the very 

 same form, even to the most minute details, is an abundant and 

 characteristic fossil of the Coralline Oolite of Pickering.^ Of the 

 second section with straight longitudinals and a flat whorl, G. 

 echinatum,'^ von Buch, might be selected as the nominal representa- 

 tive. C. GaUeni, Leek., would fall in here and likewise the variety 

 in the Coralline Oolite identified with C. Bussiense, D'Orb. This 

 section usually has four spirals. It is hardly necessary to say much 

 more with regard to such divergent forms as are depicted in Figs. 3, 

 6, and 7, beyond the fact that they are very rare. The variety Fig. 

 3 occurs where the group is rather numerous and given to sporting ; 

 whilst the vtiriety Fig. -6 occurs where the group is extremely rare, 

 and where possibly the forms were pauperized. The form Fig. 7 

 might be entitled to more distinct recognition. 



As regards distribution in the Inferior Oolite of other districts in 

 England, we seem to have but little evidence of the occurrence of 

 this group. No specimens answering to any of the vai'ieties have 

 been seen by me from Bi-adford Abbas, etc., nor does Mr. Tawney 

 notice any species of Cerithium amongst the Dundry Gasteropoda. 

 Neither has it been detected by Mr. Walford in the Inferior Oolite of 

 North Oxfordshire. Tlie species in the Great Oolite referred by 

 Morris and Lycett to C. qiiadricinctum may belong here. On the 

 Continent we may always suspect its presence when we see such 

 names as C. quadrilineatum, (jramdato-costatum, muricato-costatum, 

 echinatum, etc., in lists of fossils. Coming to the higher horizons, 

 in Hebert and Deslongchamps' work on the Callovian of Montreuil 

 Bellay, we recognize in C. Lorieri, H. and D.,^ the average form 

 with 5 spirals and arcuate longitudinals, and in their "(7. grawdato- 

 costatum, Qiienst,"* we see the section to which C. Culleni h Aon gs, 

 and for which C. echinatum is perhaps the most appropriate name. 



' Specimens from this horizon near Weymouth have the longitudinals more closely- 

 set, and the whorls are without the constriction towards the base. 

 - Quenst. Der. Jura, p. 417. 



■^ Bull. Soc. Linn. Norm. vol. v. p. 41 (sep. mem.), pi. vi. fig. 2. 

 ^ ^oL at. p. 38, pi. vii. fig. I. 



