128. Mr. F. M‘Coy on some new genera and species of 
from these the vertical lamelle radiate to the cireumference, 
-where they are cornected by the small transverse vesicular 
plates forming the narrow external cellular zone. — palace 
I propose this genus for a number of corals exceedin sly 
abundant in the mountain limestone, but hitherto classed by 
Prof. Phillips, Mr. Lonsdale, and others with Lithodendron. This 
latter genus was originally proposed by Schweigger (Beobach- 
tungen, &c. tab. 6) to include, Ist, the Oculina of Lamarck, in- 
cluding the type of Blainville’s Dendrophyllia ; and 2ndly, a di- 
vision, which allowing the previously constituted genus Oculina 
to stand for the first division, becomes the real type of his ge- 
nus, and the four references he gives to Esper’s ‘ Pflanzenthiere’ 
as examples of this genus are typical examples of the group 
subsequently named Lobophyllia by Blainville ; this latter name 
therefore becomes a mere synonym of Lithodendron and should 
be laid aside, unless, as many writers seem inclined, it be used 
for the short, wide species with lobed discs, and thus ‘leave Litho- 
dendron for the more slender cylindrical forms : although there 
is no clear line of separation between the groups, it may be con- 
venient to retain both names for those extreme forms, but in no 
case can the Siphonodendra of the mountain limestone be 
brought in any close relation with those recent and mesozoic 
types. The differences are briefly these: Ist, Siphonodendron 
increases by lateral buds,—JLithodendron by a lateral elongation 
and gradual division of the old cup and dichotomous fissure of 
the stem; 2nd, Siphonodendron has a narrow tubular axis and 
wide conoidal diaphragms, while Lithodendron has a large cel- 
lular axis and no diaphragms. I have illustrated those pomts in ~ 
the accompanying sketch. Cladocora of Ehrenberg agrees in ex- 
ternal form and mode of branching with Siphonodendron, but has 
the internal structure here represented in Lithodendron. 
Cladochonus brevicollis (M‘Coy). 
Sp. Char. Slender stem-like neck of each cell about 1 line long 
and half a line in diameter, the upper end suddenly swelling 
to a cup-shaped cell about 2 lines long and 1] line in diameter, 
curving downwards at an angle of about 135°, the point of 
junction of the cup and the stem giving origin, at an angle of 
45°, to the stem of a second cell similar to the first, but imeli- 
ning in the opposite direction, and in like manner giving ori- 
gin “from its upper convexity to a third and that to a fourth, 
&c. perfectly similar cell, forming together an erect, regularly 
zigzag corallum. 
From its regularly angular mode of growth or connexion of 
the large drooping bell-shaped cups, inclining in opposite direc- 
