18 
temxocheilus derbiensis, sp. nov. 
by wheeltox hind, m.d., b.s., f.r.c.s., f.g.s. 
(Read Nov. 20th, 1913). 
c.f. Nautilus latus de Koninck 1878, Ann. Mus. d'liist. Nat. de la Bel- 
giqiie. Tom. II. ; Pt. I., p. 110, PI. XXIV, Figs. 3, a, b, c. 
The specimen on which this species is founded was obtained from 
a small quarry on the east of the lane leading from Thorpe to Tissing- 
ton, Derbyshire. The horizon of the quarry is that of the Upper 
Dibunophyllum zone, and the fauna is rich in the characteristic brach- 
iopods of the zone. 
The specimen (Plate I) consists of three whorls and is entirely 
camerate and no indication of the body chamber is preserved. It has 
been impossible to completely expose the neanic and nephionic stages. 
Specific Characters. — Shell of moderate size, involute, expand- 
ing gradually. Inner whorls well exposed. Umbilicus large and open, 
its outer margin angular and tuberculate, its sides only slightly convex. 
The greatest transverse thickness of each whorl is from outer margin 
to outer margin ; whorls at least 4. The peripheral margin of the 
whorl is broad and almost flat, near the margin it may be very slightly 
depressed before it is raised into the keel-like margin, which is tuber- 
culate, the tubercles being separated from each other by about three 
camerse, and having the extent of almost one camara. 
The camerse are numerous, about 28 in the last remaining whorl 
of the specimen. The septa are concave on the sides and pointing 
forward at the peripheral margin, but on the periphery only slightly 
concave. The siphuncle is central. 
Test, thin, ornamented by many close fine striae. 
Measurements. — Greatest diameter, 78 mm. ; Periphery, 56 mm. 
Horizon and Locality. — Upper Dibunophyllum zone. Car- 
boniferous Limestone quarry east of Tissington Hall, Derbyshire. 
Observations. — The specimen under description is much too 
broad and the periphery much too flattened to be referred to Tenino- 
