186 
CEISIXA. 
Dimensions. 
Diameter of zooecia 
Diameter of aperture 
Fide Pergens. 
•2 mm. 
•06 „ 
Disteibution. 
Foreign : 
Seuonian — Maastrichtian : Sainte-Colombe, Manche ; Royan. 
Santouian : Saintes, etc., Charente-Inferieure. 
Coniacian: Tours, Ste. Paterue, and Joue, Indre-et-Loire ; 
Yilledieu, Loir-et-Cher. 
Turonian or Coniacian : Les Roches, Loir-et-Cher. 
Affinities. 
The zoarial characters of this species are veiy different fi'om 
those of R. oUiqua : in this species the aspect is Fenestellid, 
whereas in R. ohliqua it is rather that of Ramipora ; but one 
of the specimens figured by d’Orbigny as R. ohliqua (viz., pi. 610, 
fig. 6) has the meshes of the same shape as in the Museum 
specimen referred to R. ligeriensis. R. girondina is a variety with 
square meshes. The zoarial characters of this species are veiy 
similar to those of Retecava clathrata ; but the apertures are not 
confined, as in Retecava^ to the anterior part of the zoarium. 
LIST OF SPECIMEIS^S. 
? 42,817. Calcare psammitico. De Castello. 
? 42,818. Calcare psammitico. Merone. 
Two specimens showing dorsal surfaces of two reticular Bryozoa are 
labelled R. ligeriensis. But they are only casts in a sandstone, and are 
generically indeterminable. 
D. 1046. A broken zoarium 25 mm. broad by 27 mm. high. Senonian. 
France. Old Coll. 
TmEEPEESENTED SPECIES, 
gradata (Leymierie), 1851. 
Syn. Cricopora Leymerie, 1851. Type Pyren. par. a Craie : Mem. Soc. 
geol. France, ser. 2, vol. iv. p. 191, pi. ix. fig. 7. 
Char. — Branches laterally greatly compressed : apertures in curved rows_ of 
about nine in a series, forming well raised ridges. 
Distrib. — Senonian — Maastrichtian : Bois de la Barade, near Gensac, Haute- 
Garonne, in Calcaire a Orbitolites. 
