part 1] 



STRATIGRAPHY OF THE SHALES-WITH-' BEEF.' 57 



Agassiceras striaries. A. striaries, on the other hand, is found 

 in the 11 feet of marls below this, in association with other species 

 o£ Agassiceras and Amioceras. The bottom 2 feet of the lowest 

 division have not yielded Agassiceras (which, however, continues 

 below the Shales- with-Beef), but contain a peculiar new species of 

 Amioceras. The three lowest horizons of the lower division 

 correspond with the upper part of Oppel's ' BucJclandi- 1 Bett.'' 



The following scheme summarizes the divisions hitherto de- 

 scribed l : — 



(9) Microderoceras horizon. 21| feet. 74g-76a. Microderoceras birchi, 



Cymbites spp., Xipheroceras spp., Arietites tumeri at the extreme top. 



Microderoceras birchi, Arietites plotti, and allied forms a foot down. 

 (8) Arnioceras-hartmanni horizon. 5 feet. 74e-74f. Amioceras hart- 



manni, A. of. hartmanni, and A. cf. patti near the top. 

 (7) Arietites-broohi horizon. 1 foot. 74 c-74 d. Arietites brooki. 

 (6) Sulciferites [Spath] horizon. 13.j feet. 73a-74b. Amioceras spp. 



common above, scarce below ; Arietites three spp. nov., Sulciferites 



[Spath] sulcifer, S. cf. dumortieri, and 8. cf. angustisulcatus in the 



lower part. 

 (5) Horizon with Amioceras spp., but no Arietites or Sulciferites. llj feet. 



70 f-72 g. 

 (4) Paramioceras horizon. 8 inches. 70 a-70 e. Abundant Amioceras 



and Paramioceras (70 c) of several species. Agassiceras occurs, if at 



all, but rarely. 

 (3) Horizon yielding- Amioceras and Agassiceras of various species, but 



not Agassiceras striaries. 1^ feet. 62-69. 

 (2) Horizon with Amioceras and Agassiceras of various species, including 



A. striaries. 11 feet 7 inches. 55-61. 

 (1) Amioceras sp. nov. horizon. 2 feet. 53-54. No Agassiceras. 



(D) Detailed Description (fig. 2, p. 56). 



[Unless otherwise stated, the numbers after the name of a fossil are the 

 register-numbers of specimens in Dr. W. D. Lang's collection. All such 

 specimens will be transferred to the British Museum collection.] 



76 b. Paper-shales with Arietites aff. A. tumeri ; 5287-97. 



Microderoceras sp. ; 5269-70. 

 76 a. B irchi- tabular. 2 1 foot. An irregular tabular to 



lenticular limestone, often with large clots of iron- 



sulphide sticking to its upper surface. Microderoceras 



birchi, small specimens ; 5019-20, 5043-48, 4275-78. 



Cymbites cf. semicostulatus ; 5021, G. Icevigatus ; 



5022-27. Xipheroceras cf. planicosta ; British 



Museum, C. 17971. X. cf. capricomoides ; 5057-61. 



Arietites tumeri ; 5034-42, 5049-56. 

 75 b. 1 foot. Very fine paper-shales, with much decomposed 



iron-sulphide, also occasional and irregular impersistent 



beef-seams. Ostrea sp. ; 930. 



1 The ammonite names here and in the following section have been written 

 in the briefest manner possible, and can only be completely understood in 

 conjunction with Part II, by Dr. L. F. Spath, where full references are given. 



2 For a photograph of the Bu-c/ii-tabular exhibiting a broken anticline on 

 the foreshore at Moiith Eocks, Charmouth, see W. D. Lang, Proc. Geol. Assoc, 

 vol. xxv (1914), pi. 40, fig. B. 



