298 
INFERIOR OOLITE AMMONITES. 
The material of this species is decidedly insufficient. The little example agrees 
with Vacek's figures ;^ and it differs from either of the other species described 
because its whorls show small hair-like, somewhat closely-set ribs, with very rudi- 
mentary spines, at a time when the others have well-marked ribs twice as far apart, 
and also fairly strong spines. 
The little specimen figured, which was collected by Mr. Darell Stephens, F.Gr.S., 
is the only example of the species I have seen. It came from the Go^icavum-zone 
of Bradford Abbas, and must therefore be regarded as a survival of Vacek's 
species, which is found in a somewhat earlier horizon at Cap San Vigilio. 
Biologically, Zurcheria pertinax is a later development than the other species 
described from the Goncavum-zone ; but as it is geologically earlier at Cap San 
Vigilio it must be presumed to belong to a separate sub-branch of the genus. 
Figs. 21, 22 of PI. XLIX give two views of the only example known to me. 
The ribs are perhaps rather too prominent. 
PoEEiGN Species oe Zurcheria. 
As this is a well-marked genus, the members of which have only been figured 
recently, and are therefore but little known, I append a short note on the two 
species which have not been found in this country. 
Zdrcheria pdgnax (Vacek). 
1886. Hammatoceras pugnax, Vacek, ' Ool. Cap San Vigilio,' pi. xvi, figs. 
1 — 4. A small species with whorls at first smooth, later unispinous, and after- 
wards bispinous. Very rudimentary keel. Short tongue-like process to the mouth 
border. Distinguished from other species by the two rows of spines. Opalimm- 
MurcMnsonse-zone ; Cap. San-Vi^ilio, ^y^'^ ' 
ZUROHEEIA UbALDI |Z)onW^M|. 
1885. Zurcheria Ubaldi, Douville, Zone Amm. Soiverhiji, ' Bull. Soc. Greol. 
France,' 3e serie, t. xiii, pi. i, fig. 8. A costate species, a further development 
of Z. inconstans, from which it differs especially in being more included, and having 
broader whorls. Its inner whorls are not preserved, but the spines, if present, 
evidently made an early departure. It is the type of Douville's genus, but, | 
1 It may be noted that the suture- line given by Vacek is more ornate than the suture possessed i 
by my little specimen, so far as it can be seen through the crystalline test, and it is certainly inucb 
more ornate than that shown by the other species I have described. 
