444 
DR. G. J. HINDE ON BEDS OF SPONGE-REMAINS IN THE 
Family Anomocladina, Zittel. 
39. Mastosia neocomiensis, Hinde (Plate 45, figs. 2-2 k ; op. cit., ii., p. 57 ; Plate 10. 
fig. 4). —Spicules with spherical or sub-spherical centres, from which short arms or 
rays, from three to five in number, extend in various directions. Pays usuallv 
simple, though occasionally bifurcate near their ends. They terminate in slightly 
concave expansions. The nodes are about - 22 mm. in thickness, and the rays from 
•12 to '27 mm. in length, by ‘62 mm. in thickness. 
L. G. S , Haslemere, Tilburstow Hill, Petworth, U. G. S., Haldon, Warminster. 
Family Rhizomorina, Zittel. 
40. Chenendopora, sp. (Plate 45, figs. 3, 4-Ad). — Branching spicules of irregukr 
form, their surfaces covered with blunted spines or tubercles. Length '53 mm. by 
’085 to '15 mm. in width. 
L. G. S., Haslemere, Tilburstow Hill. U. G. S., Blackdown, Warminster, Penzle- 
wood. 
Family Tetracladina, Zittel. 
41. Ragadinia, sp. (Plate 45, figs. 5, 5a, 6).— Small, four-rayed spicules of the 
skeleton ; one of the rays is reduced to a prominent tubercle, whilst the others are 
irregularly annulated. 
L. G. S., Haslemere, Tilburstow Hill. U. G. S., Warminster. 
42. Siphonia, sp. (Plate 45, figs. G, 6 a—6f), — Four-rayed spicules of the skeleton; the 
rays usually smooth, sub-equal, and branching at their extremities. 
L. G. S., Tilburstow Hill, Sevenoaks. U. G. S., Blackdown, Haldon, Warminster, 
Penzlewood, Merstham. 
Spicules of the dermal layer of Tetracladine Lithistids (Plate 44, figs. 1-15). 
These spicules occur in an almost unlimited variety of form, but as suggested by 
Oscar Schmidt,'" they all appear to originate from modifications of the summit-rays of 
the trifid spicule. The simplest form of dermal spicule in these sponge-beds consists 
of three horizontally extended simple rays with irregular lateral lobate extensions, and 
a minute ray or shaft at right angles to the others (figs. 4, 4a). This simple type is, 
however, of rare occurrence; the large majority of the dermal spicules are derived 
from forms in which the three primary rays are symmetrically bifurcate, and each of 
the subdivisions is variously lobed and branched in a horizontal plane. Thus in one 
of the less modified examples (figs. 1, la) the rays of the typical spicule are merely 
expanded laterally and sinuated; in another the lateral expansion is increased, and 
* ‘ Die Spongier, des Meerbusen von Mexico,’ l stes Heft, 1879, p. 22. 
