596 



S. S. EUCKMAN ON AMMONITES FROM 



and I have some specimens which very much resemble Steph. 

 Humphriesianum, var. subcoronatum (Oppel), both in the number of 

 ribs and in other respects, but have short ears. 



Steps: anoceeas lingtjifeeum (d'Orb.). 



1845. Ammonites linguiferus, d'Orb. Terr. Jurass. pi. 136. 

 1856. A. linguiferus (d'Orb.), Oppel, Juraform. p. 376, no. 40. 

 Locality. Zone of Stephan. Humphriesianum at Oborne : very 

 rare. 



I possess one specimen with the termination ; it has a small plain 

 ear projecting from the side. 



Stephanoceeas zigzag (d'Orb.). 



1845. Ammonites zigzag, d'Orb. Pal. Franc, pi. 129. figs. 9, 

 10, 11. 



1856. A. zigzag (d'Orb.), Oppel, Juraformation, p. 378, no. 45. 



Of this species there are two forms, a thick and a thin one. They 

 are found, however, in the same bed in the same localities, and are 

 similar in all other respects. 



The thick primary ribs, so conspicuous in the small specimens, 

 gradually disappear as the fossil becomes larger, and give place to 

 small rounded primary ribs, which come much closer together, some- 

 times dividing into secondary ribs, and sometimes passing straight 

 round the ventral area without dividing at all. 



Localities. Parkinsoni zone at Broad Windsor, Crewkerne Sta- 

 tion, &c. 



I have no specimen with the termination ; but the body-chamber 

 is very long, as I possess one specimen with a body-chamber nearly 

 one whole whorl in length,, and yet it does not show even a sign 

 of the termination. 



Stephanoceeas polymeetjm (Waagen). 



1867. Ammonites polymerus, Waagen, Geogn. Pal. Beitrage, 

 p. (99) 605. 



1845. A. Brongniarti, d'Orb. (non Sowerby), Terr. Jurass. pi. 137. 

 figs. 1, 2. 



1881. A. Brongniarti, J. Buckman (non Sowerby), Quart. Journ. 

 Geol. Soc. vol. xxxvii. p. 64, fig. 5. 



Locality. This species occurs at Oborne, in a whitish sort of 

 marl, with Sphceroeeras Sauzei. 



In the young state it very much resembles the thin form of 

 Stephan. Humphriesianum ; but when adult it is far more like a 

 Sphceroeeras. 



Sph^eoceeas Sauzei (d'Orb.). 



1845. Ammonites Sauzei, d'Orb. Terr. Jurass. tab. 149. 



1856. A. Sauzei (d'Orb.), Oppel, Juraformation, p. 375, no. 37. 



1867. A. Sauzei (d'Orb.), Waagen, Geogn. Palaont. Beitrage, 

 p. (100) 606. 



