APPENDIX. 



[Extracted from the Geological Magazine. Vol. V. No. 3. 

 March, 1868]. ^3 i , 



ON ACTINOCEBAS BACCATUM, A NEW SPECIES OF 



OETHOCERATITE FKOM THE WOOLHOPE LIMESTONE. 



By Henkt Woodward, F.G.S., F.Z.S. 



[PLATE VIII.] 



THE fossil about to be described was obligingly sent to me by 

 Dr. Bull, of Hereford, having been happUy rescued from the 

 remorseless hammer of the road-mender, by Eichard Johnson, Esq., 

 the Town Clerk of that city. It exhibits the shell in section, fractured 

 longitudinally, and embedded in a hard compact mass of dark blue 

 Woolhope Limestone, which may be seen well exposed in situ in 

 the Little Hope quarries, near Woolhope, from whence the block 

 which contams the fossil was derived. Dr. BuU informs me that 

 the Woolhope Limestone from these quarries is always used for 

 road-metal in the surromiding district. 



It is most faithfully delineated (of the natural size) in the ac- 

 companying hthograph (Plate VIH.), by the able pencU of Dr. Bidl. 



The fossil has been fractured so as to remove the upper surface, 

 exposing seven perfect and two fractured beads of the siphunclei 

 and giving evidence of ten septa ; the chambers formed by which 

 remain partially hollow and are partly filled by calcareous spar. 

 None of the exterior wall is visible from which the nature of the 

 ornamentation of the shell, if any, might have been ascertained, 

 but the interior portion is so characteristic of the genus that I have 

 no hesitation in referring it to Actinoceras. 



That genus is characterized as follows : — " Siphuncle very large, 

 inflated between the chambers, and connected with a slender central 

 tube by radiating plates." ' 



Of the species referred to this genus five are British, namely, 



Actinoceras Brongniartii, Portl. Lr. SUurian, Tyrone. 



Brightii. Sowerby, U. „ Malvems. 



„ nummularium, Sowerby, „ Tortworth. 



giganteum, Sowerby, Cai'b. L. Yorkshire,' etc. 

 „ pyramidatum, M'Coy, „ Ireland. 



The Woolhope fossil most closely resembles A. pyramidatum, of 

 M'Coy, both m the beaded form of the siphimcle and the general pro- 

 portions of the chambers, but the beads of the siphuncle are much 

 less spherical in A. pyramidatum, and the sides of the chambers form 

 a less acute angle at their junction with the outer wall of the shell 

 than in the fossil before us.^ 



1 See " Woodward's Manual of the Mollusca," p 58 



' Compare figure on Plate VIII. with M'Coy's figure "in Carbonif. Foss. of Ireland, 

 1 232 fi^' 11 ^^ Barrande's "Syst. SUur. de Boheme (Cephalopoda) " vol. u., 



