W. S. EucUeston—On the Yorkshire Oolites. 127 



same, it clearly belongs to a well-known Liassic group. If we 

 except this and the very doubtful Troclius Leckenbyi which may be 

 a Pleurotoniaria, there are no other representatives of the genus in 

 any of the three zones of the Inferior Oolite of Yorkshire. But the 

 Dogger contains rather abundantly one species of the allied genus 

 Trocliotoma — the widely-ranging T, calix. 



From the Cornbi-ash upwards Pleurotomaria is rather better repre- 

 sented, and one species is quite abundant ; but this has affinities 

 with Oxfordian rather than with Lower Oolite forms of other 

 districts. For further observations with respect to the higher beds 

 see Corallian Gasteropoda (Geol. Mag. 1881, page 63 of separate 

 Memoir). 



79. — Pleurotomaria granulata, Lycett, non Sow., 1863. Plate 

 III. Figs. 8, 8a, 86, 9, and 10. 



1863. Fleurotomaria granulata, Sow., Lycett, Suppl. Gt. Ool. Moll. p. 24, pi. 31, 

 fig. 8. 



Compare also 



Fleurotomaria Miinsteri, Ecemer, 1839, Ool Geb. p. 44, pi. 20, fig. 12. 

 ,, - punctata, Goldi'uss, 1844, t. 186, fig. 6, non Sow. 



,, Aonis, D'Orb., Brauns, Mit. Jui-a, p. 188. 



,, species, Hudleston, Cor. Gast., Geol. Mag. 1881, PI. IV. Fig. 2. 



Bibliography, etc. — The true PL granulata of Sowerby is an 

 Inferior Oolite fossil well known to every collector from the beds in 

 Dorset and Somerset, and ditiers considerably from the species now 

 under consideration. I have already discussed this question at some 

 length in the Corallian Gasteropoda (p. 64 of separate copy), with 

 reference to a specimen of Pleurotomaria from the Lower Corallian 

 Limestones of Wydale. It is true that our Cornbrash fossil belongs 

 to what Prof. Seeley would call a " demoid " type, which has 

 connection through varieties with Sowerby's I. 0. species. But 

 the inspection of a large number of I. 0. specimens convinced me 

 long ago, as it did the late Mr. Tawney, that the Yorkshire 

 specimens referred to PI. granulata, Sow., must be regarded as 

 specifically distinct. Not only so, but the fossils of the Yorkshire 

 Cornbrash approach much nearer to PI. Miinsteri, Eoem., as also 

 does the fossil from the Lower Limestones of Wydale, 



The specific names " granulata," reticulata, fasciata, etc., have 

 been bestowed in former j'ears with such a liberal hand that the 

 mind becomes somewhat fogged in its endeavours to remember the 

 various authors and their identifications. It is difficult to saj'- whether 

 most mischief is done by retaining such names, by adopting othei'S 

 already existing which are nearer the mark, or by inventing fresh 

 ones. As the present is a work confined mainly to the illustration 

 of local palseontology, it has been considered best to adopt the first 

 course. At the same time I am perfectly aware that it leads to con- 

 fusion, and that PL granulata, D, non A, non B, non C, is a stumbling- 

 block to students and a sad tax upon the memory of all. 



Descriptions. — Specimen from the Cornbrash (zone 4), Scarborough. 

 Leckenby Collection. Figs. 8, 8a, 86. 



