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BRITISH JURASSIC SPONGES. 
Genus.—CorYNBELLA, Zittel. 
1878. Studien iiber fossile Spongien, III. Abhandl. der k. bayer. Akademie der Wiss., 
Cl. ii, vol. xiii, pt. 2, p. 125. 
Sponges simple or compound. The individual forms are club-shaped, cylindrical, 
or subspherical, with thick walls. Their summits are truncate or arched. Cloacal 
cavity tubular or funnel-shaped, frequently not extending to the base of the 
sponge, but passing down into a bundle of vertical canals. The aperture or 
osculum usually with radiating furrows of open canals. Arched radial canals open 
into the cloacal cavity. Outer surface usually with small ostia of fine incurrent 
canals which have a downward oblique direction. Basal portion sometimes with a 
compact dermal layer. Skeletal fibres of three-rayed spicules; tuning-fork 
spicules and four-rayed spicules are present in some species. 
In outer form the sponges of this genus greatly resemble Peronidella, but they 
are readily distinguished by the development of the canal system. It is doubtful 
if the Triassic forms included by v. Zittel in this genus possess a similar spicular 
structure to those from the Jurassic rocks described below. 
28. CORYNELLA LYCOPERDIOIDES, Lamourouw, sp. Plate XV, figs. 3—3 h. 
1821. Hatirruoa Lycoperpiomwes, Lame. Exp. méthodique, p. 72, pl. Ixxvin, 
fig. 2. 
1840-7. SreHonta tycoperpiomweEs, Michelin. Icon. Zoophy., p. 251, pl. lviii, 
fig. 6. 
1878. CoryNeELLa LycorerpriorpEs, Zittel. Studien, i, p. 126. 
1883. _ -= Hinde. Cat. Foss. Sponges, p. 180. 
Sponges simple, depressed globular, pear-shaped, or obtusely conical, rarely 
corrugate or lobate, supported on a short cylindrical stem, usually attached at 
its base to a fragment of shell or other organism. Small specimens are not more 
than 11 mm. in height by 6 mm. in thickness; the body of the largest example 
met with is 20 mm. in diameter. The stems do not appear to exceed 10 mm. in 
length. 
At the summit the circular oscule slightly projects; it is from 2°8 mm. to 
4 mm. in width: in full-grown specimens the rim is entire, but in others short 
furrows radiate from it; the surface of the sponge is usually smooth, and dotted 
irregularly with small oval ostia, from -25 mm. to*5 mm. in width, which are 
bounded by the flattened fibres ; and in addition to these there are small, irregular, 
