CORALLIFERI. 407 
M. Lamouroux separates from them 
PLEXAURES, 
Of which the thick bark, with non-salient cells, effervesces but 
slightly in acids(1). 
EUNICEA, 
Where the bark, organized like that of the Plexaures, is furnish- 
ed with projecting mammille, from which the Polypi protrude(2). 
MurRIcka, 
Where the moderately thick bark is provided with projecting mam- 
millz, covered with imbricated and rough scales(3). 
PRIMNOA, 
Where the elongated mammille become imbricated by hanging 
one over the other(4). 
In the second tribe, that of the 
LITHOPHYTA, 
The internal axis is of a strong substance and fixed. In 
Isis, Lin. 
This axis is ramous, and has no cells or cavities on its surface. The 
°. 
verriculata, ld. XVII;—G. wmbraculum, Id., X;—G. exserta, Id., XV, 1, 2;—G. cera- 
tophyta, Id., Il, Be 3; IX, 5, 6, 7, 83 >a EE eR G. viminalis, Id., XII, 1;—G. 
verticillaris, Id., UW, 4, 5;—G. Briareus, Id., X1V, 1, 2, &c. 
(1) Gorgonia crassa, Gm., Ac. des Sc., 1700, pl. ii;—G. swberosa, Ell., Corall., 
XXVI, f. p, q, r;3—G. friabilis, Lamour., Sol. and Ell., XVIII, f. 3. 
Bs (2) Gorgonia antipathes, Seb., Ul, civ, 2, evii, 4;—Hun. limiformis, Lamour., 
Sol. and Ell., XVIII, f. 1;—£wun. clavaria, Id., Ib., 2;—Hun. mammosa, Lamour., 
add. to Sol. and Ell, LXX, f. 3. 
(3) M. spicifera, Lamour., or Gorg. muricata, Gm.; App. to Sol.and Ell., LXXI, 
f. 1, 2;—M. elongata, Lamour., Id. f. 3, 4. 
(4) Gorg. reseda, Gm.; Sol. and Ell., XIII, f. 1, 2. 
