58 
OSCULIPOEID^. 
keeps in it one of that author’s species, viz. Idmonea Jilix, 'which is 
a worn 0. truncata. 
One species of Truncatula must he included among the Cancellata, 
as remarked on p. 109. 
Osculipora differs from Cyrtopora by the fact that its groups 
of apertures do not open all round the stems, the reverse side 
having none. 
The most difficult question with this genus is its separation from 
Hornceosolen, which, however, has the apertures spread over the 
whole obverse face. When specimens show both obverse and 
reverse faces there is no difficulty, except when the surface of an 
Osculipora is so worn that the zooecia are broken, and the openings 
thus made may resemble true apertures. The chief difficulty is 
with specimens of Romceosolen which are embedded in the matrix 
and show only the reverse face ; the ends of the reflexed pinnules 
then resemble the fasciculi of Osculipora. Thus the species figured 
by von Hagenow as Retepora striata ^ shows only one face, and 
there is no absolute evidence as to whether it be an Osculipora or 
Romceosolen, though the identity of the characters that are shown 
with those of d’Orbigny’s Truncatula gracilis renders it probable 
that the species is a Romceosolen. 
1. Osculipora truncata (Goldfuss), 1827. 
Synonymy. 
Petepora truncata, Goldfuss, 1827. Petref. Germ. vol. i. p. 29, pi. ix. fig. 14. 
,, ,, Moiven, 1829. Corall. foss. Belg. : Ann. Acc. Groning. 1828, 
p. 36. 
,, ,, Kloden, 1834. Verst. Brandenburg, p. 264. 
,, ,, Milne-Edwards, 1836. In Lamarck, Hist. nat. Anim. Vert. 
2nd ed., vol. ii. p. 283. 
,, ,, Milne-Edwards, 1838. Mem. Crisies: Ann. Sci. nat. ser. 2, 
vol. ix. p. 219. 
,, ,, von Hagenow, 1839. Mon. Biig. : Xeu. Jahrb. 1839, p. 281. 
,, ,, von Hagenow, 1846. In Geinitz, Grundr. Verst, vol. ii. 
p. 591. 
Idmonea ,, de Blain^dlle, 1830. Zooph. : Diet. Scii Nat. vol. lx. p. 385. 
,, ,, de Blainville, 1834. Man. Act. p. 420. 
OsouUpora ,, d Orbigny, 1849. Gen. nouv. Bry. : Ilev. Mag. Zool. 
ser. 2, vol. i. p. 503. 
,, ,, pars, d’ Orbigny, 1850. Prod. Pal. vol. ii. p. 267. 
* Von Hagenow. In Geinitz, Grundr. Verst, vol. ii. (1846), p. 591, pl.xxiiiB, 
fig. 3. 
