224 
This form seems nearly allied to Orthis lunata , Sowerby, in the general 
shape of the shell; the radial lineation is, however, stronger and closer in the 
latter species. 
Orthis (Hebertella) vespertilioides, sp. nov. 
Plate XXI., Fig. 6. 
Shell sub-rectangular. Hinge-line undulate ; lateral edges strongly curved. 
Ventral valve with a strong median sinus, which gives to the shell the appearance 
of a bilobate orthid. Marked with numerous fine riblets radiating from the 
umbo. Height 4.5mm.; width 8mm. 
The general form and markings of this species remind one of 0. vespertilio, 
Sowerby, but the latter is higher, and therefore more quadrate. 0. 
vespertilio is a well-known species in the Bala beds of Shropshire, in England. 
Orthis (Hebertella) raristriata, sp. nov. 
Plate XXI., Figs. 7 and 7a. 
Shell sub-quadrate, hinge-line wider than the rest of the shell. Lateral 
margins curved outwards posteriorly. Median sinus sharply defined. Surface 
of shell with vestiges of a few short costse arranged around the marginal portion. 
Height 5.3mm.; width 8.6mm. 
The shape of the valves and their outlines remind one of Ortliis sinuata, 
J. Hall, from the Hudson group, Cincinnati, Ohio,* but the lineations on the 
surface are much more numerous than in our specimen. 
Orthis (Bilobites) divaricata, sp. nov. 
Plate XXI., Fig. 9. 
This species resembles 0. (B.) varica, Conrad, in form, but it has a slightly 
longer hinge-line, coarser riblets, and a greater divergent lobation of the 
anterior part of the shell. The costae are bifurcate, and transversely marked 
by numerous fine striae running nearly concentrically with the border of the 
shell. Height 5mm.; width 6.5mm. 
Rhynchonella (Camarotoechia ?), sp. 
Plate XXI., Fig. 10. 
The specimen figured is a sinus area of a ventral valve of a rhynchonellid. 
The shell is strongly sulcate and subdivided anteriorly into twice the number 
of riblets. 
PELECYPODA. 
MODIOLOPSIS, J. HALL. 
Modiolopsis (?) knowsleyensis, sp. nov. 
Plate XXI., Figs. 11 and 12. 
The figure here given represents a minute and thin-shelled form found in a 
hard ochreous fissile rock at Heathcote. It appears to be a right valve. The 
hingement is of the Dysodont order or edentulous. Adductor scars are visible 
at the extremities ; the anterior scar is crossed by numerous fine lines running 
parallel with the hinge-line. Interior of shell marked by fine concentric, and 
sometimes laminate lines. Length 4mm.; width 2.4mm. 
* See also Hall and Clarke, Nat. Hist., New York, vol. viii., Braehiopoda, pt. I., 1892, 
p. 198, PL V A., Figs. 1-8. 
