200 
EETECAYA. 
Idmonca commntata, Marsson, 1887. Ibid. p. 29, pi. ii. fi". 10. 
,, JiUformis, d’Orbigny, 1853. Bry. Cret. p, 744, pi. 750, figs. 1-5. 
,, carantina {non Orb.), Vine, 1893. Corapl. Bep. : Rep. Brit. Assoc. 
Diagnosis. 
Zoarium of stout or delicate brandies, which arc dichotomous. 
The reverse axis is rounded and longitudinally* striated. The 
obverse face is also well rounded, so that the transverse section 
is elliptical. 
Apertures in oblique scries of from two to five, but usually 
three ; the series are subalternate, and confined to the obverse 
face. The peristomes arc well raised. The series arc distant, 
sometimes very distant. 
Dimensions. 
Disteibution. 
British : 
Upper Chalk : Broniley ; Magee Island, Antrim. , 
Middle Chalk : Chatham. 
Foreign : 
Danian : Faxoe. 
Senonian — Maastrichtian : Maastricht ; St. Pierre ; Heer ; Geuleni ; 
Affinities. 
Goldfiiss included in his Retepora disticha a miscellaneous series 
of specimens which were first properly* described by* von Hagenow. 
That author refigured Goldfuss’ ty*pe, and founded the ‘ species ’ 
^ pseudodisticha,'' which Pergens has proposed to merge in R. carinata. 
It is only with great hesitation that I venture not to follow in this 
course, for it is quite possible that the carinata form may* be only 
the older basal portions of the pseudodisticha ; but as the evidence 
ior this seems still inconclusive, it is safer to retain the two forms 
Pergens, 1890. Revision, p. 346. 
1892, p. 308. 
Diameter of branch ... 
Diameter of zooecia 
Diameter of apertures 
Distance of transverse series of apertures 
Fide Pergens. 
*5-3 mm. 
Ciply ; Friedrichberg, near Aachen. 
Campanian: Riigen. 
Santonian : Salzberg, near Quedjiaburg'. 
