HOKXERA. 
365 
ryEEPEESEXTED SPECIES, 
degrossouvrei (Pergen>% 1895. 
8yx. Filicavea dachjim, pat's. d'Orbigny. 1853-4. Bn\ Crct. p. 940, pi. 773^ 
figs. 8-1 r. ' 
,, ,, pd's, Persrens, 1890. EeWsion. p. 351. 
,, degrossouvre'i , Pergens. 189.5. Bry. Ai’cbe de Leves : Bull. 
Soc. beige Geol. yoI. viii., Pr. M). p. 135. 
Char. — Zoarium dendroid: macula? biserial and petaloporoid. Eeverse surface 
marked by parallel, rarely branched ridges. 
Distrir. — Senonian — Maastidchtian : Meudon. 
Santonian : LWrcbe de Leves, near Chaiires. 
HORNER A, Lamouroiix, 1821. 
SYXOXYilS. 
Millepora, pars, Linna?us. 1768. 
Retepwa. pars, von Ilagenow, 1839. 
Idaxoma, pars. Busk (187-5). 
Retihonxera, Kircbenpauer (1869). 
? Stigmatoechos, ^larsson (1887). 
? Phorxnonotos, pars, Marsson (1887;. 
DrAGXOSls. 
Horncrkla} with the zoarium composed of an axial zooecial bundle 
and a thick lamellar epitheca on one or both snrfaces. Apertures 
in suhregular transverse series, or sometimes in snhaltemate [rows, 
^laculee irregularlj distributed. Tuhuli on reverse suilace present 
or absent. 
Typp: Species. 
Roniera frondiculata, l^amowi'QW's., 1821. Eecent. 
Affixities. 
This genus was founded on a bring Indo-Pacific and ^lediterranean 
species, and in it are included two groups of species — one with a hare 
obverse face and the other with that face covered by reticular 
epithccal ridges. The genus begins in the Senonian, and is veiy 
abundant in the Lower Cainozoic. 
Stigmatoechus, !Mars., appears to be the most primitive form of 
Jlornera^ and may be worthy of subgeneric distinction. According 
to Marsson, it is separable from Hornera by the absence of 
