Yol. 52.] IN YORKSHIRE AND LINCOLNSHIRE. 181 



Thus Belemnites pistillirostris and B. cristatus are together more 

 restricted in their range than B. jaculum, to which they are closely 

 allied ; while B. Jasikowi and B. obtusirostris similarly occupy a 

 portion only of the zone of B. brunsvieensis. 



As several of the forms, however, seem to occur indiscriminately 

 throughout the realm of the allied species, I think that for strati- 

 graphical employment, as distinct from their more strictly palae- 

 ontological study, it will be found serviceable to retain for our 

 present purpose the broader system of nomenclature. It must 

 therefore be understood that in the stratigraphical notes in the 

 following pages the specific names of the zonal belemnites, and to 

 a less extent of the zonal ammonites also, will be freely used in 

 this broader sense, embracing all the closely-allied variations. 



Since 1889 I have several times had opportunities for examining 

 exposures of the strata on the foreshore at Speeton, and have been 

 enabled thereby to collect much new palaeontological material, and 

 to fix the horizon of a few forms whose exact position had been 

 doubtful. These results, as regards the cephalopoda, are sum- 

 marized in the Table facing p. 184, where the species as determined 

 by Prof. Pavlow are arranged according to their stratigraphical 

 position. 



[On revisiting Speeton while this paper was in the press I had the 

 good fortune to find in the uppermost part of the section, of which 

 our knowledge is still incomplete, among the recent slips under the 

 Chalk escarpment 450 yards south of Speeton Gap, a small strip of 

 brown marly clay, 2 or 3 feet thick, which contained belemnites of 

 a type that I had not hitherto seen at Speeton. In structure, size, and 

 outline this form shows close afiinities to Belemnites jaculum, but 

 differs markedly from that species in the character of the alveolar 

 extremity : most of the specimens possess a slight lateral groove 

 in the subalveolar region. It seems very probable that this may 

 be the form recorded from Heligoland by Prof. Dames (op. jam 

 cit.) as B. fusiformis, Yoltz, which in that island occupies a zone 

 between the beds with B. minimus and those with B. brunsvi- 

 eensis. 



I could find no other fossils along with this belemnite, and the 

 band which contained it was bounded on all sides by slips ; but 

 below the brown clay was a mass of black pyritous clay with 

 Ammonites Deshayesii, and above it dull black clay without fossils 

 such as I have elsewhere seen to occur beneath the marls (A) with 

 B. minimus, and there is much likelihood that the slips have preserved 

 the true sequence of the beds. — April 22nd, 1896.] 



The reiterated ' contention of the Rev. J. F. Blake 2 that ' Port- 

 landian ' beds may after all exist, as supposed by Prof. Judd, 



1 'Annals of British Geology for 1892' (London, 1893), Introductory 

 Eeview, p. xviii. 



2 ' Geology of the Country between Eedcar and Bridlington,' Proc. Geol. 

 Assoc, vol. xii. (1891) p. 115. 



o2 



