292 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [April 9, 



sparingly, that I have not found more than one or two specimens ; 

 but of the Anodon (?) I have taken not fewer than fifty specimens, 

 varying from less than three-quarters of an inch, to six inches in length ; 

 and, although some of the specimens exhibit a slight difference of 

 form, yet a general uniformity of character and contour seems to 

 refer them all to one species*. 



The last and lowest deposit (No. 4, p. 290) does not appear to be 

 rich in fossils ; but this apparent destitution may result rather from 

 an imperfect examination than from inherent barrenness. This bed 

 consists principally of mottled clays, such as are usually supposed to 

 be unfossiliferous. By the discovery of the dorsal rays oi Hybodus 

 in these clays t> however, I have satisfactorily proved that this opi- 

 nion is erroneous ; although the almost total exemption of these red- 

 stained clays from organic remains which are distributed through the 

 strata both above and below them, seems to support this general 

 impression. 



3. On the Pal^ontological and Stratigraphical Relations 

 of the so-called " Sands of the Inferior Oolite." By 

 Thomas Wright, M.D., F.R.S.E. 



[Communicated by Prof. Ramsay, F.G.S.] 



Contents. 

 Introduction. 

 Section and fossils at Leckhampton Hill, Gloucestershire. 



„ „ at Crickley Hill, Gloucestershire. 



„ „ at Beacon Hill, Gloucestershire. 



„ ,, at Frocester Hill, Gloucestershire. 



„ „ at Wotton-under-Edge, Gloucestershire. 



„ „ at Bradford-Abbas, Dorsetshire. 



„ „ near Bridport, Dorsetshire. 



Oolitic character of the Cephalopoda-bed. 

 Occurrence and place of the Cephalopoda-bed on the Continent. 

 Table of the Fossils of the Cephalopoda-bed. 

 New Species of Molluscs from the Cephalopoda-bed. 



Introduction. — The calcareous sands which lie between the limestone- 

 beds of the Inferior Oolite, above, and the clays of the Upper Lias, 

 below, have from the time of Dr. William Smith until now been re- 

 ferred to the Oolitic group, and described in books as " the sands of 

 the Inferior Oolite." These sands exhibit a very uniform litholo- 

 gical character throughout their entire range in England, although 

 they differ much in thickness in different localities, thinning out or 

 even altogether absent in some places, but attaining a considerable 

 development in others ; in this respect they do not differ from the 

 great oolitic liraestone-beds themselves, forming so important a 

 feature in the geology of Gloucestershire ; as those bold mural 

 escarpments of freestone which impart such a picturesque effect to 



* This Anodon (?) is one of at least twenty species of Unionidee in my collection 

 from the Hastings rocks, of which the majority are new. 

 t At Bulverhithe. 



