Ixxx BRITISH FOSSIL CORALS. 
2. Genus PTEROGORGIa. 
Ehrenberg, Corall. des Rothen Meeres, p. 144, 1834; Dana, op. cit., p. 647, 1846. 
Differs from Gorgonia by the polypi being bifarious. 
Typ. sp., Pterogorgia anceps, Ehrenb., loc. cit., p. 145. 
3. Genus BEBRYCE. 
Philippi, Zoologesche Beobachtungen, in Archiy. fur Naturgeschichte, yon Erichson, vol. viii, p. 35, 1842. 
Arborescent compound polypi, resembling Gorgonia by their corneous sclerobasis, but 
differing from the preceding genera by not being retractile. 
Typ. sp., Bebryce mollis, Philippi, loc. cit. 
4. Genus PHYLLOGORGIA. 
Differs from Gorgonia by the coenenchyma not constituting a cylindrical sheath around 
the ramifications of the sclerobasis, but extendmg between them so as to constitute large 
foliaceous, frondiform Jaminee, the two surfaces of which are studded with the calices of 
the individual polypi. 
Typ. sp., Phyllogorgia dilatata ; Gorgonia dilatata, Esper, Pflanz. Gorg. tab. xli. 
5. Genus Puycocoreta. 
Sclerobasis flabelliform, divided into digitated lobes, and composed of delicate corneous 
fibres united into laminee, the two sides of which are covered with the ccenenchyma, 
and densely studded with numerous non-prominent calices. 
Typ. sp., Phycogorgia fucata ; Gorgonia fucata, Valenciennes, Voyage de la Venus, tab. xi, fig. 2. 
6. Genus Muricra. 
Lamouroux, Exposit. Method. des Polyp. p. 36, 1821. 
Differs from Gorgonia by the calices bemg surrounded with imbricated squammule, 
but not supported on long, verruciform, moveable appendices, as in Primnoa. 
Typ. sp., Muricea spicifera, Lamouroux, op. cit., tab. xxi, figs. 1, 2. 
7. Genus Primnoa. 
Lamouroux, Hist. des Polypiers Flexibles, p. 440, 1816. 
Differs from the preceding genus by the polypi constituting long verruciform subpedi- 
culated appendices, which are capable of motion at their bases. 
