BELLE ROPH ON RUTHVENI. 55 



band narrow, slightly raised, with fine median line along it ; lunula! very delicate 

 and numerous. Mouth with basal inner angle of lip reflected across umbilicus and 

 recumbent on whorl- Surface of shell crossed by strongly arched fine transverse 

 striae meeting slit-band at about 20°, with traces of low rounded similarly arched 

 transverse ridges ; transverse lines crossed by fine somewhat broken oblique 

 revolving lines set at rather wide equal distances apart and inclined to slit-band 

 at about 60°. 



Dimenswns [28080]. — Height of shell, 30 mm.; width of dorsum, 32 mm.; 

 height of outer whorl, 15 mm. 



Horizon. — Wenlock Limestone. 



Locality. — -Near Ledbury. 



Remarks. — -This shell is undoubtedly distinct from B. wenloclcensis, and in 

 shape and ornament more resembles U. bohemica*, Barr., 1 from Stage Ff2. From 

 the nature of the ornamentation it might seem that this species should be placed 

 in the genus Bucania, but the closed umbilicus, reflected basal lip and umbilical 

 callosity are more important, and it is preferable to place it in BeIJeroj>hon. Only 

 the one specimen [28080, Mus. Pract. Geol.] is known to me. 



3. Bellerophon ruthveni (Salter MS). 



1873. Bellerophon ruthveni, Salter, Cat. Camb. Silur. Foss. Woodw. Mus., p. 186. 

 1891. Bellerophon ruthveni, Salter, Woods, Cat. Type Foss. Woodw. Mus., p. 96. 

 1901. Bellerophon ruthveni, Salter, Reed, Geol. Mag. [4], vol. viii, p. 358, pi. xv, figs. 5, 6. 



No further details can be added to the description of this species given 

 by me in 1901, for no better specimens are available. The species is imperfectly 

 known and cannot be defined precisely. Salter's definition was as follows : 

 " Smaller than B. dilatatus and with the band angular, and the whorls angular 

 where the band becomes so. Very common, 1^ inches wide." The aperture is 

 transverse and widely expanded with rounded lateral lobes ; there is a wide, 

 sharply V-shaped sinus in the outer lip ; the slit-band is very narrow and sunk in 

 a groove between slightly elevated margins. The dorsum of the outer whorl near 

 the mouth seems to be more strongly arched and carinated, but this may be due 

 to the crushing of the specimens. There seem to be traces of one or two spiral 

 thread-like lines running parallel and close to the slit-band and slightly diverging 

 towards the mouth, and there are faint transverse simply arched growth-lines on 

 the lateral lobes. 



Horizon. — Kirkby Moor Flags (Up. Ludlow). 



Locality. — Benson Knot, Kendal. 



1 Perner, op. cit., p. 132, text-fig. 94 e. 



