DIASTOPOKA. 123 



DISTRIBUTION. 



BRITISH : 



Cornbrash : Bedford (fide Vine). 

 Great Oolite : Hampton, near Bath. 

 Inferior Oolite : Postlip. 



FOREIGN : 



Bathonian : Marquise, near Boulogne ; Ranville. 



Bajocian: Chavier, Haute- Saone; Croixille, Calvados (fide Michelin) ; 

 Gueret, Sarthe (fide D'Orbigny) ; St. Quentin and Montvaux, near 

 Metz ; Plappeville (fide Friren). Zone of Parkinsonia parkinsoni : 

 Fontoy and Gorze (fide Terquem). 



Description of Figures. PI. VI. Fig. 5. Part of zoarium of a 

 normal variety, X 18 dia. Great Oolite: Hampton Common. 

 B. 2302. PL VI. Fig. 6. Part of base of a zoarium with gonocyst, 

 of var. wrighti, X 18 dia. Inferior Oolite: near Leckhampton. 

 Brodie Coll. D. 2142. Fig. 7, p. 20, shows initial cell of a 

 colony. Fig. 4, p. 16, shows the transition from the Berenecoid 

 to the Diastoporoid condition. 



Affinities. In this species I include D. terquemi, Haime, which 

 appears to be founded on a part of the zoarium where the lines 

 of peristomes are more oblique, and the apertures therefore some- 

 what quincuncial. The figure given by Haime of D. davidsoni 

 is exceptionally regular, and the normal distribution is shown 

 in PI. VI. Fig. 5. D. wrighti must also be included in this species, 

 as it has all the essential characters. Haime's specimens appear 

 to be young and worn. 



This species may be distinguished from D. foliacea, Lamx., 

 by having a lower peristome, shorter zooacia, and regularly 

 distributed peristomes. 



The species is represented in the Cretaceous by D. campicheana 

 (D'Orb.). 1 



LIST OF SPECIMENS. 



B. 2302. Great Oolite. Hampton Common. Figd. PI. VI. Fig. 5. 

 B. 2301. 



B. 4837. ,, Loc.? Holl CoU. 



D. 2142. Form wrighti. "With gonocyst. Inferior Oolite. Near Leckhampton. 

 Brodie Coll. Figd. PI. VI. Fig. 6. 



1 Bidiastopora campicheana, D'Orbigny, Pal. franq. Terr. cret. t. v. p. 800, 

 pi. Dcclxxxiv. figs. 6-8, which shows both the regular and irregular distribution 

 of the peristomes. 



