EICKMAN— ON CYRENA DULWICHIENSIS. 
211 
a narrow, upright, ribbon-like band, pressed against the preceding 
whorl, and feebly crenulated by the lines of growth ; in well 
preserved specimens the margin, immediately in front of the 
sutural band, presents two or three obscure concentric furrows. The 
last whorl is somewhat attenuated towards the base ; the aperture 
is entire, rounded in front, narrow behind, and very long, nearly 
equalling four-fifths of the entire length of the shell ; the columella 
is obscurely and very obliquely twisted, and anteriorly is much 
curved ; the outer Hp is shghtly arched, simple, and sharp on the 
edge ; the inner hp is posteriorly thickened and narrow, anteriorly 
effuse, flattened, and reflexed, forming an angular ridge on the colu- 
mella, and confluent with the outer lip. 
Size. — The dimensions of my largest specimen, if it were perfect, 
would be. Axis, 2 inches and 2-12ths nearly ; Diameter, 1 inch. 
Explanation of Plate V. 
PiTHARELLA RiCKJiANi. — Fig. 1. — Front View. Fig. 2. — Back View. Fig. 3. — 
Portion of Pytharella, showing twist in the columella. From specimens iu 
the collection of F. E. Edwards, Esq., to whose liberality we are indebted for 
this plate. 
NOTICE AKD DESCRIPTION OF CYBENA DULWICH- 
IENSI8. 
Bt Chaeles Rickman, Esq., Hon. Curator of Lambeth Museum. 
In a former communication to the " Geologist," treating of the 
fossil fau.na and flora observed in Lower Eocene strata passed 
thi'ough at Dulwich and Peckham, in the construction of the Great 
South High Level Sewer, I mentioned the fact of having discovered 
in a shelly conglomerate at Dulwich, a new species of the estuarine 
genus Cyrena, which I proposed to call Cyrena Dulioicldensis. In 
sinking the main shaft, at a depth of fifty to sixty feet, this con- 
glomerate occurred in nodular masses in green sheUy sand, inter- 
calated with wedge-like bands of stiff black clay, highly charged 
