20 STRATA EXPOSED IN CONSTRUCTING FILTON-AVONMOUTH RAILWAY. 
VI. PALEONTOLOGICAL NOTES. 
Mytilus cloacinus^ sp. nov. 
Anterior outline slightly arcuate, ventral margin rounded, posterior 
margin gently convex as far as the hinge line, which is straight and 
equals one-third the length of the shell. Beak angle 40 degrees. Valves 
obtusely carinated from the beaks to the antero-ventral border, sloping 
evenly from the carina to the posterior margin, and sharply on the 
anterior side. Growth halts well marked. 
The specimens are generally casts : some fragments of the shell 
which have been observed do not exhibit any ornament. 
Dimensions, length 42 mm,, width 21 mm., thickness 12 mm. 
Geological position ; Lower Rhsetic. 
Remarks — The specimen figured is a nearly complete cast from the 
bone bed at Aust Cliff. Examples have also been collected from the 
bone beds at Sedbury and at Charlton. This fossil appears to be not 
uncommon on the bone bed horizon, but, so far as I can discover, 
it has been found at no other level. 
Cardinia concinna. Sow ; C. aff. regularise Terquem, Vaughan. 
A. Vaughan, Quart. Journ. Geol. Soc., Vol. lx. (1904), 
PI. xviii., fig. 4, p. 204. 
This shell is rather common in the upper part of the Avicula 
contorta shale at Charlton. 
Protocardium, { Cardium J Rhillipianume Dunker. 
W. Dunker, “ Palseontographica I ” (1847), t. xvii., f. 6, p. 116. 
Cardiufii rhceticume Merian. 
P. Merian, Geol. Bermerk. u.d. Nordl, Vorarlberg (1853), 
t. iv., fs. 40 and 41, p. 19. 
It may be that Merian’s shell is specifically distinct, but, in prac- 
tice, it has been found impossible to separate the Rhaetic specimens, 
of this genus from those found in the White Lias and Pleiiromya beds. 
Pleuroinya ( Pteromya ) crowcombelae Moore, Tate. 
R. Tate “Yorkshire Lias” (1876), PI. xiii, fig. 10, p. 406. 
The identity of Moore’s small shell from the Rhsetic, with the much 
larger examples from the White Lias and Pletiromya beds, is doubtful. 
Modiola minimae Sow, Moore. 
C. Moore, Quart. Journ. Geol. Soc., Vol. xvii. (1861), PI. xv., fig. 26, p. 505. 
The Modiola thus indicated in this paper has not been found outside 
the White Lias, in which, after Pleuro7nya crowco7nbeiae it is perhaps 
the commonest fossil. It is specifically distinct from the small Modiola 
minimae Sow, and should receive another name. 
