Ixxxiv BRITISH FOSSIL CORALS. 
7. Genus LitvaRta. 
Valenciennes MSS., Cat. of the Zoophytes in the Museum of Paris. 
Resembling Veretillum, but having a long well-developed axis, quadrangular and 
tapering towards its lower part, inflated, claviform, pitted and echinulate at its upper end. 
Typ. sp., Lituaria phalloides, Valenciennes, loc. cit. ; Pennatula phalloides, Pallas, Miscel. Zool.; 
tab. xill. 
8. Genus CAVERNULARIA. 
Valenciennes, loc. cit., MSS. 
Resembling Veretillum, but having in its centre a large fibrous tube divided longi- 
tudinally into four cavities, and not containing any calcareous or horny axis. 
Typ. sp., Cavernularia obesa, Valenciennes MSS. 
9. Genus RENILLA. 
Lamarck, Hist. des Anim. sans. Verteb., vol. ii, p. 428, 1816. 
Polyp-mass explanate, unifacial, reniform, with a short, slender peduncle, containing 
a central cavity as in Pennatula, but not having any solid axis. 
Typ. sp., Renilla Americana, Lamarck; Pennatula reniformis, Ellis and Solander, p. 67; Shaw, 
Miscel. iv, tab. exxxix. 
The genus GrapronitHus (Linneus, fer Scan. 1751,) appears to have more affinity 
with Virgularia than with any other recent zoophyte. The polype mass is slender, virgate, 
and often becomes bifurcate by the progress of growth. The axis projects at the inferior 
extremity of the stem, and is often bifurcate. 
Example, Graptolithus ramosus, Hall, Paleont. of New York, tab. Lxxiii, fig. 3. 
The genus WessTEr1A, nob. appears to be very similar to Graptolithus by its general 
structure, but offers also a certain resemblance to some Sertularide and to certam Bryozoa. 
In the present state of our knowledge, the natural affinities of these fossil zoophytes are 
indeed so obscure, that we hesitate to place them in any of the preceding zoological 
divisions, and prefer leaving them in the zacert@ sedis. 
Typ. sp., Websteria Crisioides, nob., tab. vii, fig. 5. 
