614 MR. C. B. WEDD ON THE [ISToV. 1 898, 



lower ; and yet below the laminated marl, in the crystalline bauds 

 with Thecosmilia, there occur Cidarisflori gemma (m some abundance), 

 Tet^ehratuJa maltonensis, Thamnastrcea concinna, and other forms 

 never found below the highest oolite at Upware. 



The conclusion, then, seems inevitable that no oolite has been lost 

 here, and that the passage-beds and Elsworth Eock really come just 

 below the E-ag horizon. In this case there would be another anti- 

 cline (or a fault, of which I have found no evidence anywhere in the 

 neighbourhood) between the Southern Quarry and the well- and 

 field-sections. 



It appeared, then, desirable to re-examine the evidence on which 

 the Elsworth Kock has been correlated with the Lower Calcareous 

 Grit, by the light of more recent additions to the faunas both of the 

 Elsworth and St. Ives Eock and of the Corallian generally. About 

 a hundred species have been found at Elsworth and St. Ives. On 

 taking the Yorkshire Corallian area and comparing the Elsworth 

 and St. Ives fauna with those of (1) the Lower Corallian Oolite, 

 Lower Calcareous Grit, and still lower British formations, and (2) the 

 higher Corallian beds and higher formations, it appears that some 

 76 Elsworth and St. Ives species are found in the Lower Corallian 

 Oolite and Lower Calcareous Grit or in Oxford Clay or still lower, 

 while 71 are found above the Lower Corallian Oolite. Of these 76 

 forms from the Yorkshire Lower Corallian and below, one is a doubt- 

 ful Elsworth form, and another, not found higher in Yorkshire, is so 

 found elseAvhere in England; while, of the 71 higher Corallian species, 

 2 that are not found lower dqwn in Yorkshire are so found elsewhere. 



A comparatively thin and impure calcareous deposit such as 

 the Elsworth Rock, covering no great area and for the most part 

 isolated in the midst of thick clays, might perhaps preserve a 

 greater proportion of Oxford Clay species than more extensive and 

 thicker Corallian rocks did. Moreover, there probably still remain 

 in our Corallian lists certain forms wrongly identified with species 

 of the better-known Lower Jurassic faunas. This, of course, tends 

 towards an exaggeration of the number of Elsworth Lower Corallian 

 forms as compared with those of the Upper. At any rate, if we 

 neglect occurrences in the Oxford Clay and below, we find 58 species 

 common to the Elsworth Eock with the Lower Calcareous Grit and 

 Lower Corallian Oolite of Yorkshire ; 3 of these, not found higher 

 in Yorkshire, being so found elsewhere, while as many as 69 forms 

 are common to the Elsworth Eock with higher Corallian beds of 

 Yorkshire, 2 of these, not found lower in Yorkshire, being found 

 lower elsewhere in England. 



The late T. Eoberts pointed out that though 5 Elsworth species 

 (Astarte robusta, Cucullcea claihrata^ Cardium Craiufordi, Hinnites 

 ahjectus, and Isocardia glohosa) are elsewhere found only below the 

 Corallian, yet they are all species of long range and not peculiar to 

 the Oxford Clay. One of these, Binnites abjectus, is now recorded 

 from the Malton Oolite, in which Waldheimia hucculenta has also 

 been found. This is one of the species mentioned by Mr. Eoberts as 



