26 
THEONOID^. 
TJNEEPRESENTED SPECIES, 
depressa, Hamm, 1881. 
Syn. Patenaria depressa, Hamm, 1881. Bry. mastr. Ob. -Sen. i., Cycl. p. 33. 
Chah. — Z oarium round, very tbin, flat or concave. The zooecial bundles are low 
and their upper edge is Avell rounded ; they branch once or repeatedly ; their 
arrangement may be fan-shaped or regularly radial. The edges of the bundles 
on the edge of the colony have about three series of small cells. 
Distrib. — Senonian — Maastrichtian : Maastricht. 
Aff. — P ossibly a near ally of Actinopora diadema (Goldf.). 
THEONOA, Lamouroux, 1821. 
[Expos. Meth. p. 82.] 
Synonyms. 
Tilesia, pars, Lamouroux, 1821. 
PhyUofraticia, Marsson, 1887. 
Theonoa, pars, Ulrich, 1900. 
Diagnosis. 
Theonoidae xvith a massive or frondose zoarium, attached at the 
base ; apertures in multiserial, raised, branching hands, xvhich 
radiate from the base to the top edges of the fronds ; apertures 
crowded on the margin. 
Type Species. 
Theonoa clathrata, JjdimoxxYou'K., 1821. Bathonian : France. 
Afeinities. 
A Theonoid with erect fronds. The genus began in the Jurassic. 
UNREPRESENTED SPECIES, 
grandis (Marsson), 1887. 
Syn. Phyllofrancia grandis, Marsson, 1887. Bry. Riig. : Pal. Abh. vol. iv.- 
pt. i. p. 43, pi. iv. fig. 2. 
Char.— The frond is 10 mm. wide and long ; the bands of apertures are triserial 
or quinquiserial. Interspaces smooth. 
Distrib. — Senonian — Campanian ; Biigen. 
