

I 

 55 mm. 



[[ 



(G\ 15775) 



50 nun. 



c. 



37 „ 



. c. 31 „ 



c. 



20 „ 



. c. IS „ 



c. 



50 „ 



. c. 46 ,, 



BELLEROPHON WENLOCKENSIS. 57 



strong lunulas. Mouth slightly expanded towards base; dorsal sinus forming very 

 obtuse V (about 100°- — 110°), followed by narrow, straight, open slit which extends 

 fully one-third the length of the whorl ; lateral lobes rounded, arched forward. 

 Surface of shell ornamented by transverse arched, strong, sublamellose squamous 

 lines, rather closely-set. but not always equidistant or equal, somewhat undulated in 

 places, curving back gently to meet the slit-band at about 60°, becoming coarser 

 and less regular near the margins of mouth (with short, closely-placed Hue cross 

 lines in interspaces of some specimens). 

 Dimensions : 



Height of shell .... 



Thickness at umbilicus 



Height of outer whorl near mouth 



Width of 



Horizon. — (1) Wenlock Limestone; (2) P Llandovery Beds. 



Localities. — (1) Ledbury; Wenlock; Croft, Malvern; Woolhope ; Dudley. (2) 



The Frolic, Haverfordwest; Blaen-y-cwm. 



Remarks. — Of this species Sowerby gave no specific diagnosis, but merely said: 



"This species differs a little from the species \B. tenuifascia\ of the Carboniferous 



Limestone ('M. ('.,' vol. v, p. 109, pi. cccclxx, figs. 2, 3) figured in ' M. C.,' but it is 



difficult to indicate a real difference owing to the calcareous spar having taken the 



place of the shell. We assign it provisionally the name /'. wenlockensis. Loc. 



Wenlock; Croft, Malvern." 



Sowerby's figured type-specimen [6708], in the Jermyn Street Museum, is 



from Ledbury, and is an internal cast covered with crystalline calcite. There is a 



more perfect example (G. 15775) in the British Museum from the same locality ; 



but neither of them shows any ornament or has the shell preserved. Better 



specimens from Dudley and Woolhope are in the Sedgwick Museum. McCoy gave 



the following definition: " Globose, periphery and sides obtusely rounded ; umbilicus 



very small, mouth transversely lunate, rounded at the sides, forming a deep, 



obtuse V-shaped sinus in the middle, the sides of which meet at an angle of 105°, 



which is also the angle at which the coarse, very irregular, close, subimbricating 



ridges of the surface meet the keel ; keel about half a line wide, strongly defined, 



prominent (traces in parts of very minute spiral striae roughening the transversely 



8 

 arched ones). Width at mouth 2^ inches, proportional diameter — — , diameter of 



47 13 



mouth — - , diameter of umbilicus — . Rare in the Wenlock Limestone of 

 100 100 



Woolhope." 



The specimen n/627 on which McCoy based this specific description is in 



the Sedgwick Museum, and it is from this one that I have drawn up the diagnosis 



of the species. 



8 



