SPINIGERA. 105 
lations. At the junction with each keel and the varices a spine is developed and 
generally nearly at right angles to the axis of the shell, sometimes with a slight 
anterior deflection. These spines are always situated about two-thirds down the 
whorl; above the base of each spine is a slight corrugation of the varix but no 
more than one spine on each side of the whorl. 
Aperture ovate-oblong to subquadrate; no regular wing, since the anterior 
lateral spine springs from the varix and not from the outer lip; canal long and 
straight. N.B.—There seems a certain amount of irregularity in the development 
of the spines, but on the whole the arrangement is distinctly bilateral, though in 
some cases the spines appear better developed on one side than on the other. 
Relations and Distribution—Nearly related to the succeeding species, Sp. 
longispina is in this country eminently characteristic of the Humphriesianus-zone, 
where alone I have succeeded in finding it. The three figured specimens are all 
from the Sherborne district. The Sauzei-bed at Oborne contains a very inflated 
variety. Mr. Wilson has lately found a specimen in the iron-shot Oolite of Dundry, 
which seems to present features intermediate between this species and those of 
the one next described, though inclining towards Sp. longispina. 
24, SPINIGERA RECURVA, Sp. nov. Plate III, figs.5a,56; 5c¢,d,e; 5f,g, h. 
Description : 
Length (full size) ‘ . 22 mm 
Ratio of minor to major axis of width : » 402100 
Shell rather short, fusiform, and moderately compressed. Apical whorls four, 
subglobular and plain (fig. 5 4), constituting the opening of a very convex spiral 
angle; next whorl angular and costated longitudinally; the succeeding whorls 
of the spire (three or four) have either no longitudinals or at best very faint ones, 
but are spirally ornamented throughout, and betray a tendency to bicarination 
which varies in different specimens but is generally well marked. The body-whorl 
exhibits a third carina, sometimes also visible in the penultimate. The chain of 
bilateral varices is more or less continuous, but a spine is always sent out on both 
sides where the varix crosses the lower keel (fig. 5 e). The direction of the spines 
is irregular, those on the body-whorl have mostly a tendency to curve upwards. 
Aperture very nearly quadrate and graduating into a wide and straight canal. 
There is no actual wing, but in the well-preserved specimen, fig. 5 a, the spines are 
seen to be grooved, and the groove in the anterior lateral spine is seen distinctly 
to communicate through a notch in the outer lip with the aperture, hence it may 
also be said to have the function of a wing. 
14 
