180 MR. G. W. LAMPLTTGH ON THE SPEETON SERIES [May 1 896, 



the fauna of the various deposits. "With the material already- 

 collected it would indeed have been possible to present mucja 

 ampler lists. But the mischief done by the publication of swollen 

 catalogues of hasty determinations, not in these deposits alone, but 

 throughout the whole range of the Secondary rocks, has been so 

 great, and the precise recognition of many of the forms in the 

 present state of their nomenclature is so difficult, that I have 

 thought it advisable to restrict myself as far as possible to the use 

 of those few species which have been adequately described and 

 figured rather than risk adding to the existing confusion. 



That the fauna of these rocks has been hitherto much neglected 

 by British palaeontologists is no doubt mainly due to the fact that, 

 so far as the British Islands are concerned, it is comparatively 

 restricted both in its occurrence and its interest, the fossils of 

 these marine deposits affording no ready points for comparison with 

 those of the equivalent freshwater strata of the south of England. 

 Over large areas of the continent of Europe, however, as was so 

 clearly shown 25 years ago by Prof. Judd, 1 the conditions of deposit 

 are more directly comparable, and there is a close relationship in 

 the fauna. Recently Prof. A. Pavlow 2 has made a very careful 

 study of the cephalopoda of these rocks with this relationship in 

 view, and his monograph for this branch of the fauna affords a 

 secure basis from which to discuss many questions of stratigraphy 

 and correlation. But not until the rest of the fauna has been 

 taken in hand, and in like manner studied and compared with that 

 of the Continental equivalents of these deposits, will it be possible 

 to compile satisfactory lists of the fossils, or to consider to full 

 advantage the broader aspects of the subject. 



II. Etjrther Notes on the Speeton Section. 



In my former paper I proposed to divide the clays of the Speeton 

 section into zones by means of the belemnites, which are by far the 

 most abundant and the most characteristic fossils contained in the 

 deposit. 3 Prof. Pavlow has since shown that each type of belemnite 

 selected for this purpose may be considered palaeontologically as a 

 group of allied forms presenting variations of specific value. These 

 variations will no doubt in some cases enable us to trace out minor 

 zones. 



1 ' Additional Observations on the Neocomian Strata of Yorkshire and 

 Lincolnshire, etc.,' Quart. Journ. Geol. Soc. vol. xxvi. (1870) pp. 326-348. 



2 ' Argiles de Speeton et leurs Equivalents,' Bull. Soc. Imp. d. Naturalistes 

 de Moscou, n. s. vol. v. pp. 181 & 455 (1891-92). (Also published separately, 

 Moscow, 1892.) 



3 At that time some objection was raised to my selection of the belemnites 

 as the zonal fossils ; but, as I then stated, it was quite evident that no other 

 fossils would serve the purpose so well, and I am pleased to find that this 

 statement has been fully borne out and justified by further investigations. As 

 Pavlow has shown, the study of the belemnite-fauna of the epoch is prolific in 

 results throughout Europe. Prof. Dames, in a recent paper, ' TJeber die 

 G-liederung der Flotzformationen Helgolands,' states for that island 'hier 

 wie dort sind die Belemniten die leitenden Fossilien,' Sitzungsber. k. preuss. 

 Akad. Wissensch. Berlin, vol. 1. (1893) p. 1031. 



