44 GASTEROPODA OF THE INFERIOR OOLITE. 



abundant than at Stoford and Coker. The species of Amberleya, too, are rather 

 numerous, and differ somewhat from those of the Sowerbyi-bed ; there are also 

 species of Onustus allied to 0. pyramidatus, Phil., which seem rather peculiar. 



The real " fossil-bed " of Bradford Abbas occurs in two blocks. This stone 

 when peroxidized is also a yellow ironshot Oolite, but it is much softer and more 

 marly than the Paving-stone bed. Hence it is favorable for development, and few 

 fossil-bearing rocks in the English Oolites work better. The fossils are in good 

 spathic condition for the most part, but there is some variety in this, as also in 

 the matrix, due probably to slight differences of position and possibly of horizon. 

 As regards the name Soiverbyi-bed, since none but the initiated can pretend to know 

 what the " true Sowerbyi " is like, it is difficult to say whether it occurs here. 

 Mr. S. S. Buckman, if I remember rightly, once told me that it was very scarce. 

 The most characteristic Ammonites of this bed, and indeed of this horizon through- 

 out North Dorset, are those allied to Am. concavus, which we must regard as a near 

 relative of Am. Murchisona. As far as my experience goes, if the " true Sowerbyi " 

 has any resemblance to Sowerby's figure in the ' Mineral Conchology,' that form is 

 far more common in the so-called Sauzei-bed of Oborne than in the so-called 

 Sowerbyi-bed of Bradford Abbas. It may be that in that part of Germany whence 

 Oppel, and after him Waagen came, the true Sowerbyi is plentiful in the bed that 

 bears its name, but such is not the case with us. Now, there can be no doubt, as I 

 hope has been already made clear, that the zone in question corresponds to a por- 

 tion at least of the Norman "Maliere;" indeed, this is shown to be the case by 

 Waagen himself. Yet I cannot find in the works of M. Eugene Deslongchamps 

 any evidence that the " true Soiverbyi " is in any way characteristic of the Norman 

 " Maliere," though Am. concavus is held to be so. As this is the most important 

 bed for Gasteropoda hitherto discovered in the English Oolites, there should be as 

 little obscurity as possible about its position in the geological scale, and we should 

 endeavour, for the Dorsetshire District, to seek our parallels in Normandy rather 

 than in Wurtemberg. Since it is recognised as the Sowerbyi-bed, let it be known 

 that in this country the recognition can only be granted on the liccus a non lucendo 

 principle, and that the name concavus-bed or beds would with us be far more 

 appropriate. 



It may interest some of the readers of the Palseontographical Society to know 

 that this remarkable bed, which was sedulously worked for many years by the late 

 Professor Buckman, attracted the attention of the late Dr. Wright. In the year 

 1856 the results of his impressions on North Dorset were published in the 

 ' Quarterly Journal of the Geological Society ' (vol. xiii, p. 309). Dr. Wright was 

 then disposed to correlate the Bradford Abbas fossil-bed with the Frocester 

 Cephalopoda-bed, or zone of Am. radians, and he named it the Cephalopoda-bed, 

 which for him formed a portion of the Lias. Hence Professor Buckman complained 



