606 



S. S. BTJCKMAN ON AMMONITES EKOM 



Remarks. This species was figured in the ' Quarterly Journal of 

 the Geological Society ' for February 1881, under the name of Am- 

 monites subradiatus ; but it is very distinct from, that species, the 

 umbilicus alone being sufficient to distinguish it. 



Localities. It is found in the zone of Harpoceras Sowerbyi at 

 Bradford Abbas, Halfway House, and many other places. It is 

 tolerably common. 



Amaltheus subspinatus, S. S. Buckman, n. sp. 



This species is so peculiar and distinct from all others which I 

 have met with in the Inferior Oolite, that I think it worth while to 

 mention it here, although it has not been figured. 



It is very nearly allied to Amaltheus spinatus (Bruguiere) of the 

 Marlstone. It possesses the peculiar crenulated keel, which is dis- 

 tinct ; but the crenulations are not very prominent. It has a large 

 number of whorls, and very small inclusion, but does not increase in 

 breadth at all rapidly. It has many fine angular ribs, ornamented 

 with two spines on each rib, one set being in much the same place 

 as those on Amaltheus spinatus, while the other set is on the inner 

 portion of the whorl. 



Aperture. Quadrangular. 



Dimensions. Diameter 3 inches, umbilicus 1*55, aperture from 

 back to front 0*75, across 0'67, inclusion barely any. 



Localities. It occurs in the Soiverbyi zone at Bradford Abbas, 

 Halfway House &c, but is scarce. 



The termination is like that represented by d'Orbigny(Terr. Jurass. 

 pi. 52. fig. 1) for Amaltheus spinatus — a plain single bend, much 

 produced on the ventral area. 



Oppelia Trtjellii (d'Orb.). 



1845. Ammonites Truellii, d'Orb. Terr. Jurass. pis. 117, 129. 

 figs. 1, 2. 



1849. A. Truellii (d'Orb.), Quenstedt, Jura, tab. 54. 



1854. A. Truellii (d'Orb.), Morris, Catalogue, p. 295. 



1878. Oppelia Truellii (d'Orb.), Bayle, Geologie de la France, 

 vol. iv. pi. 89. figs. 1, 3, 4 (2?, 5?). 



Occurs in the zone of Cosmoceras ParJcinsoni at Halfway House, 

 Wyke Quarry, and Burton Bradstock. 



The longitudinal lines well distinguish this species. It is also 

 ornamented with longitudinal furrows, which vary slightly in depth, 

 as also does the species in thickness. 



Oppelia stjbhadiata (Sow.). 



1825. Ammonites subradiatus, Sow. Min. Conch, pi. 421. fig. 2. 



1845. A. subradiatus (Sow.)?, d'Orb. Terr. Juras. pi. 129. fig. 3. 



1854. A. subradiatus (Sow.), Morris, Catalogue, p. 295. 



1856. A. subradiatus (Sow.), Oppel, Juraformation, p. 372, fig. 26. 



Localities. Zone of Cosmoceras ParJcinsoni at Broad Windsor, 

 Crewkerne Station, Bridport, &c. : rather common. 



