PLATE VI. 



Figs. 



1, 2. Ammonites hwivscvhif:, J. de C. Sowerby, Min. Coucli., vol. v, p. 73, 1824, pi. ccccli, figs. 1, 2. 



[Brit. Mus. no. 43950 a, 6.] 



" Specific Characters. — Discoid, carinated, umbilicated, obscurely radiated ; carina distinct ; radii 

 waved, alternatelj- long and short, slightly elevated ; umbilicus small, exposing parts of the inner 

 whorls ; apertiire sagittate. 



" One half of the diameter of the shell is occupied by the aperture, a third of the other half by the 

 imibilicus, in full grown individuals ; in young ones the umbilicus is larger. The front is obtuse with 

 a large prominent keel in the middle of it ; the sides are rather convex marked with waved, elevated 

 radii, that are broader and less conspicuous on the outer whorls of the full grown shells. In young 

 shells the aperture is oblong, rather square ; as the shell grows older, the aperture becomes longer, 

 more deej)ly notched by the preceding whorl, and narrower towards the front. 



" Found in the inferior or Iroushot Oolite, at Dundry by 6. W. Braikenridge, Esq., to whose 

 liberality we are indebted for a series of specimens." 



Fig. 



3. Amwonites siihradiatus, J. de C. Sowerby, Min. Conch., vol. v, p. 23, 1823, pi. ccccxxi, fig. 2. 



[Brit. Mus. no. 43943.] 



" Sj^eclfic Characters. — Lenticular, umbilicated, carinated, and radiated ; radii twice curved, 

 ob[s]cure excepting near the margin, where they are bifid; umbilicus small; keel entire; aperture 

 sagittate. 



" The edge of this leuticidar Ammonite is rather obtuse, and the carina not much relieved ; the 

 sides are nearly smooth, for the cuiwed radii are very obscure excepting near the edge after they have 

 become forked or divided, as some of them are, into three or even fovn* short ribs ; the thickness is 

 about one fiftli of the diameter. 



" Found several years ago on the road from Bath to Bi-istol ; it hns been broken out of a mass of 

 the Ironshot Oolite; no other specimen has reached our Cabinet." 



Fig. 



4. Ammonites corrvgalus, J. de C. Sowerby, Min. Conch., vol. v, p. 74, 1824, j)l. ccccli, fig. 3. 



[Brit. Mus. no. 43951a.] 



" Specific Characters. — Discoid, carinated and umbilicated, strongly radiated ; carina distinct ; 

 radii waved, sometimes furcated, elevated; umbilicus broad, exposing parts of the inner whorls; 

 aperture obovate ; front obtuse. 



"Eesembling the last [Ammonites Isevi-usculvs], but thicker, with more prominent radii, and a 

 broader front. 



" From Dundi'y, with the A. lieviuscuhis." 



Fig. 

 6. Ammonites hrowni, J. SowerV)y, Min. Conch., vol. iii, p. 114, 1820, pi. cclxiii, figs. 4, 5. 



[Brit. Mus. no. 43966.] 



" Specific Characters. — Discoid, with radiating undulations ; inner whorls half exposed, with large 

 tubercles upon each side ; marginal undulations many, central ones few, rising into tubercles ; front 

 rounded with a distinct keel ; aperture cordate. 



" In general appearance very much like the last [Ammonites hocnigi'], but rather thicker and 

 sufiiciently distinguished by the keel and knolis ujjon the inner volutions. 



" From Dundry, by favour of my good friend 0. W. Brailcenridge, Esq. I wish by tlie name of 

 this Ammonite to commemorate E. Brown, Esq., a gentleman of general knowledge and an excellent 

 botanist." 



