240 
GA.STEROPODA OF THE INFERIOR OOLITE. 
Relations and Distribution. — TEe most peculiar feature of Ps. heterocycla is a 
sort of reversed turriting wEicIi arises from the overlap of eacE wEorl by its 
predecessor in tEe adult or carinated portion of tEe sEell. It is tEis cEaracter, in 
conjunction witE tEe sligEt constriction of tEe wEorl, wEicE serves to distinguisE 
it from Ps. hicarinata. But tEe two forms run into eacE otEer very mucE, 
especially in tEe Bradford Abbas beds, so that they might be regarded as one 
species. In such cases, the older name, heterocycla, would seem to have the pre- 
ference, although possibly there might be no overlap of the whorls. 
It is noteworthy that Eugene DeslongcEamp’s type comes from the so-called 
Soioerhyi-hedi of the forest of Haye (Meurthe), and not from the “ Oolithe ferugi- 
neuse.” TEis shows it to be a fossil of the Lower Division, which is exactly what 
we find on this side the channel. The Coker-beds are in the Murchisonse-zone. 
TEe narrow form is extremely abundant in the concavus-hedi at Bradford Abbas, 
and this same form occurs also in the Lower Trigonia grit of Leckhampton. 
176. PsEUDOMELANiA, species or variety. Plate XVIII, fig. 5. 
Description : 
Spiral angle 
. 22°. 
Height of whorl to width 
. 1 : 1-45. 
Length 
. . 85 mm. 
This form approaches Ps. hicarinata, but has the whorls shorter, and the 
sutures do not gape so much. In the shortness of the whorl and wider spiral 
angle it more resembles the Coker variety of Ps. heterocycla. The nodosities 
are coarser than in either species. 
As a mere distinction this may be known as Pseudomelania “ robusta.” A 
single specimen from the opalinus-zone (Moorei-heds), Coaley Peak. 
177. Pseudomelania, species or variety. Plate XVIII, fig. 6. 
Description : 
Spiral angle 
. 18°. 
Height of whorl to width 
. 1 : 1-3. 
Length 
70 mm. 
This form differs from Ps. procera in the wider spiral angle and somewhat 
