EETECAYA. 
195 
moimtecl on a thickened axis. The axis and reverse face are 
furrowed by irregnlar, linearly arranged, short depressions. 
The lamina has a strong central plate, which projects as a keel. 
Apcidiires in short, vertical series of from three to five, limited 
to the obverse lamina. The walls of the zooecia below the 
aperture are usually depressed, reristomes very slightly 
raised. 
DlMEXSlOXS. 
Breadth of branch : lamina 
Reverse axis 
Thickness of branch 
Diameter of zooecia 
Diameter of aperture . . . 
Distance of transverse series 
B.M. 
B.M. 
D . 3546 . 
D . 3542 . 
1 mm. 
•7 mm, 
0 
... 1-0 „ 
2-5 „ 
1-5 ,, 
•18 „ 
... - 08--1 „ 
•11 „ 
... - 06--08 ,, 
•5 ,, 
•26 „ 
DlSTBlBUTIOX. 
Senonian — Maastrichtian : Maastricht, Falkeuherg, and Petit-Lanaye, 
Limburg ; Kunraed, 
Campanian : Riigen. 
Fig. 16 . — Rctccava lichenoides [GolM,). 
Tiguke. 
Fig. 16 . Longitudinal section showing the zooecia traversing 
the thick laminated epitheca, X 18 dia. IVIaastrichter Kreide : 
Maastiicht. Tan Breda Coll. D. 7509. 
Affixities. 
This species was chosen by d’Orbigny as the type of his genus 
Reteporidea. It differs from Retecava ramosa by the shortness of 
