CnOANITES. 
105 
Fig. a. A ventriciilite in an expanded state, 
showing the inner surface. 
Fig. b. A specimen partially contracted, exhibit- 
ing the external integument. 
Fig. c. A ventriculite more expanded, and ex- 
posing the internal cavity. 
From what has been remarked, we may there- 
fore conclude that the ventriculites were more 
nearly related to the actinia? than to the alcyonia, 
and, like the former, were capable of contraction 
and expansion. 
CHOANITES. 
Another zoophyte deserving particular mention 
is the spherical or globular species, to which the 
name of Choanites, is given in the Fossils of the 
South Downs. The fossils derived from the re- 
mains of this zoophyte are very numerous : the 
originals appear to have held an intermediate 
place between the alcyonia, properly so called, 
and the ventriculites. They are distinguished 
from the former by the central cavity in their 
superior part, and from the latter, by being des- 
titute of an external reticulated integument, &c. 
and possessing but a slight degree of contractile 
power. 
The alcyonium Jicus of Linne { figure de sub- 
stance et (Teponge et d'alcion, of Marsilli) may be 
considered as the type of the genus. “ It is of 
the form of a fig, being attached to the rocks by 
branches proceeding from its smaller end ; the 
