SPONQIIDA. # 
14 Spong. 
ZiTTEL (23) classifies the Lithistidce^ fossil and recent, as follows : the 
new genera alone are mentioned ; for the new recent genera, vide supra. 
The system has been revised by attention to hitherto unobserved micro* 
scopic characters. 
Fam. 1. — Rhizomorina^ Zitt. Skeleton corpuscles {i.e.^ spicula) irregu- 
larly branched, with root-like or knotty processes, central canal simple or 
branched. Superficial elements often resemble the skeleton-corpuscles, 
consist also of uni-axials and forked anchors. 
(a.) Skeleton corpuscles moderately branched : a short simple canal in 
the chief ray; loosely intertwined. Cnemidiastrum^ p. 109, pi. ii. fig. 8, 
pi. iii. figs. 1, 2, & 3, Corallidium, p. 110, Pyrgochonia and Discostroma^ 
p. 112, Leiodorella [L/o-], pi. ii. fig. 5, pi. iii. fig. 11, and Epistomella^ pi. ii. 
fig. 3, pi. iii. fig. 12, p. 113, Hyalotragos[^gus~\, pi. iii. figs. 4 & 6, and 
Platychonia^ pi. iii. figs. 8-10, p. 114 ; all Upper Jura. 
(b.) Skeleton corpuscles strongly branched, with fairly-wide branched 
canal, frequently knit into fibres. Bolidium, p. 114, pi. iv. fig. 8, Astro- 
holia, p. 115, Chonella, p. 116, pi. iii. figs. 6 & 7, Seliscothon[^um\^ p. 117, 
pi. iv. figs. 2-4 & 7, Verruculina, p. 122, pi. iv. fig. 1, Amphethelion[^um\ 
p. 123, pi. iii. fig. 15, Jereica^ p. 126, pi. iv. figs. 11 & 12, pi. v. fig. 1, 
Ccelocorypha^ p. 128, pi. ii. fig. 4, pi. iv. figs. 9 & 10, Scytalia^ p. 128, pi. v. 
figs. 3 & 4, Pachynion[-u7ri]f p, 130, pi. v. fig. 2, all from Chalk; 
Stachyspongia, p. 129, pi. v. fig. 5. 
Fam. 2. — Megamorina, Zitt. Skeleton elements large, elongated, 
smooth, curved, forked, or irregularly branched, with simple axial canal, 
loosely knit together ; sometimes some smaller Rhizomoriue types among 
them ; surface spicules, uni-axials, or forked anchors. Megalithista^ 
p. 130, pi. vi. fig. 4, Jura, Doryderma^ p. 131, pi. vii. fig. 1, Carterella^ 
p. 132, pi. ii. fig. 7, pi. vii. fig. 2, Chalk and Greensand, Isoraphinia 
[/sorrA-], p. 133, pi. vii. fig. 3, pi. v. fig. 8, Chalk, Heterostinia^ p. 133, 
pi. vi. fig. 3, Chalk. 
Fam. 4. — Tetracladina^ Zitt. Skeleton elements 4-ray ed, rays termin- 
ally branched or thickened, with four axial canals meeting at angles of 
120°; abundant surface spicules of various shapes. Phymatella, p. 137, 
pi. ii. fig. 1, pi. viii. figs. 2 & 3, Aulaxinia [^Aulac-~\, p. 138, pi. viii. fig. 4, 
Callopegma, p. 139, pi. ii. fig. 6, pi. viii. fig. 5, pi. ix. fig. 1, TrachysycoHy 
p. 140, pi. ix. fig. 4, Astrocladia, p. 147, pi. ix. fig. 9, Cahjmmatinay p. 149, 
pi. ii. fig. 2, pi. ix. fig. 8, Thecosiphoniay p. 148, pi. x. fig. 3, Rhacodisculay 
[cf. under recent genera], Ragadinia\Rha-]y p. 152, pi. x. fig. 2, Plintho- 
sella, p. 153, pi. x. fig. 5, SpongodiscuSy p. 153, pi. ii. fig. 9, pi. x. fig. 6 : 
all from Chalk. 
Remarks on spp. of Siphoniay Lymnoriay Ret}spcngiay with sp. n. of 
Spongia, L., with pi. ; apparently from the Palaeontological Fauna of 
neighbourhood of Cracow, made by S. Zarecznaga j Sprawozd. Kom. 
fissyogr. ii. p. 244, pi. iv. 
PaloeaciSy Milne-Edwards, generally considered a perforate Coral, is 
perhaps a Calcisponge ; cf. pi. xii. for microscopic, &c., structure. H, A. 
Nicholson & R. Etheridge, Ann. N. H. (5) iii. p. 206. 
