218 BRITISH JURASSIC SPONGES. 
26. PrronIpELLA NANA, Hinde. Plate XV, figs. 2—2 g. 
1884. Prronetta nana, Hinde. Quart. Journ. Geol. Soc., vol. xl, p. 780, pl. xxxv, 
figs. 2, 2 a. 
Sponges small, for the most part growing singly, but occasionally two or three 
individuals are attached to a common base, globular, pear-shaped, or subcylindrical, 
attached either directly by a small basal expansion or supported on a short 
pedicle. The summits are rounded or subtruncate, with a circular or elongate 
cloacal aperture from 1 mm. to 2 mm. in width. The dermal layer is restricted to 
a narrow band round the base, or is sometimes altogether wanting. The specimens 
range from 4 mm. to 11 mm. in height, and from 3:5 mm. to 7 mm. in breadth. 
The outer surface exhibits subcircular or irregular apertures, from ‘1 mm. to 
‘5 mm. in width. The fibres are stouter in some specimens than in others, and the 
apertures somewhat larger. In transverse section of the wall the fibres of the 
outer surface are sometimes ‘25 mm. in thickness, whilst those of the interior vary 
from ‘05 mm. to (14 mm. The cloacal tube extends nearly to the base of the 
sponge. The spicular structure of the fibres is very imperfectly shown : it appears 
mainly to consist of three-rayed spicules ; in some instances there is a marginal 
layer of filiform spicules. 
This species was originally founded on two small specimens from the 
Richmond well-boring ; numerous similar forms have since been obtained by Mr. 
HK. A. Walford from Shipton Gorge. Amongst these there are certain differences 
in form and size, but they are all connected by intermediate variations, and seem 
to belong to one species. 
Distribution.—Inferior Oolite. Parkinsoni-zone at Shipton Gorge, Dorset 
(Coll. E. A. Walford); and at Bradford Abbas (Mr. R. F. Tomes). Also in the 
Middle Oolite of the Richmond (Surrey) well-boring, at 1205 feet beneath the 
surface (Prof. J. W. Judd). 
Genus.—EHUSIPHONELLA, Zittel. 
1878. Studien iiber fossile Spongien, III. Abhandl. der k. bayer. Akademie der Wiss., 
Cl. ii, vol. xiii, pt. 2, p. 124. 
Syn. Scyphia, Goldfuss (in part); Siphonoccelia, Disccelia, Fromentel (in part) ; 
Pareudea, Htallon (in part). 
Sponges either simple or branching. ‘The individual spongites are cylindrical, 
somewhat contracted below, thin-walled, with a wide tubular or funnel-shaped 
cloacal cavity, which extends from the base of the sponge. Wall of the cloacal 
