196 Dr. G. J. Hinde on Fossil Calcispongie. 
spicules; but in the large majority of these, the rays are equal 
in length, they radiate from the centre at equal angles, and 
are but seldom in the same plane, but usually elevated in the 
form of a three-sided pyramid, with the fourth ray at the 
apex. No one at all acquainted with sponge-spicules would 
confound these with the spicules of calcareous sponges. 
A dermal surface-layer of large quadriradiate spicules simi- 
lar to those present in this fossil appears to be a common 
feature in several existing Calcisponges, amongst others in 
Leucaltis clathria, Hick. Mon. Bd. u. p. 159, T. 28. f. 3, 
and Leucaltis crustacea, Hiick., Mon. Bd. ii. Taf. 28. f. 1; 
but in no existing sponge is there the same disposition of the 
spicules of the interior to form anastomosing solid fibres as 
in this and other allied fossil forms ; and this character forms 
the distinctive feature of the Pharetrones, sharply marking 
them off from the families of existing Calcisponges. 
The main differences between this species and Verévcillites 
anastomans, Mantell, sp., ‘ Wonders of Geology,’ p. 636, f. 3, 
consist in its mode of growth, the chambers being spherical 
instead of cylindrical, and the upper much larger than those 
beneath. J am unable to determine if there are any differences 
in the spicular structure of the two species; for though the 
examples of V. anastomans are very abundant in the Far- 
ingdon gravels, in none are dermal spicules visible. D’Or- 
bigny has mentioned a species of Verticildites under the name 
of V. incrassata, Prodr. de Pal. vol. u. p. 186; but as the 
only reference to it, contained in the following paragraph, 
““ Eispeéce dont les tiges grossissent de la base au sommet au 
lieu d’étre cylindriques,” is obviously insufficient for satis- 
factory recognition, | have preferred to give a new designation 
to this species. 
Horizon and Locality. Upper Greensand, Warminster, 
Wiltshire. 
Coll. British Museum of Natural History (Cunnington 
coll.) ; Museum of Practical Geology, Jermyn Street. 
_Corynella rugosa, n. sp. (Pl. X. fig. 4; Pl. XI. fig. 25.) 
The examples of this species are all simple, and in form 
cylindrical, straight or curved. ‘The base is contracted to a 
minute blunted stem ; and the summit is truncate. The outer 
surface has concentric ridges, which are either continuous or 
broken up into tubercular elevations. An average specimen 
is 48 millim. in height and 18 millim. in thickness. The 
cloaca is in the form of a cylindrical tube ; the aperture at the 
summit is 4 millim. in width. The walls vary in thickness 
between 4 and 7 millim. | 
