W. D. Lang — Cretaceous Cheilostome Polyzoa. 501 



Diagnosis. Incrusting Cheilostome Polyzoa with bilateral 

 branching, and typically uniserial, though actually raultiserial 

 patches often occur owing to the smallness of the angle of branching, 

 the frequency of branching and the shortness or absence of caudse in 

 the first individuals of a branch ; zooecia monomorphic, divided into 

 a distal capitular and a proximal caudal portion which may, however, 

 be very short or even absent ; termen beaded ; extra-terminal front 

 wall well developed proximally and provided with a rhamma ; intra- 

 terminal front wall represented by a narrow bevel tending to become 

 wider proximally. 



Genotype. Charixa vennensis, n.sp. 



Distribution in time. Albian. 



Charixa. vennensis, 1 n.sp. PI. XVII, figs. 5 & 6. 



Diagnosis. As for the genus Charixa. 



Type-specimen. British Museum specimen D. 22950 ; Cowstones ; 

 Charmouth ; Coll. W. D. Lang. 



Distribution. Albian, zone of DToplites interruptus, Bed 3, and 

 zone of Mortoniceras rostratum, lower part, Cowstone horizon ; Black 

 Ven, Charmouth, Dorset. 



III. Pyripora, d'Orbigny. 2 



In 1914 3 in a paper dealing with some uniserial Cretaceous 

 Cheilostomes, I wrongly stated that d'Orbigny founded the genus 

 Pyripora on three genosyntypes in his " Prodrome de Paleontologie 

 Stratigraphique ", in 1850. As a matter of fact he had already 

 founded this genus in 1849, 2 selecting as his genotype Criserpia 

 pyriformis of Michelin, 4 and I take this opportunity of acknowledging 

 my error. Criserpia was founded by Edwards 5 for a Cyclostome 

 Polyzoan, and Pyripora, therefore, stands as the genus for Michelin's 

 species, which, though not a Cyclostome, is not easily interpreted in 

 detail from Michelin's figure. As far as can be seen from the figure 

 the termen is not beaded and there are no avicularia. It differs from 

 Serpetopora, therefore, chiefly in the shortness or absence of the 

 caudse in the angle of branching and probably in the method of 

 branching. Only a provisional diagnosis, therefore, is given. 



Provisional diagnosis. Incrusting uniserial or pauciserial Cheilo- 

 stome Polyzoa with unilateral 6 (and ? sometimes bilateral) branching ; 

 zooecia monomorphic with very short caudae or without caudse ; 

 termen plain ; extra-terminal front wall well developed proximally, 

 with no rhamma ; intra-terminal front wall represented by a narrow 

 bevel, tending to become broader proximally. 



Genotype. Criserpia pyriformis, Michelin. 4 



Distribution in time. Miocene, Falunian. 



1 From Black Ven, the cliff from which the type-specimen came. 



2 d'Orbigny, 1849, Eevue et Magasin de Zoologie, 2nd series, vol. i, p. 499. 



3 Lang, 1914, Geol. Mag., Dec. VI, Vol. I, p. 436. 



4 Michelin, 1848, Iconographie Zoophytologique, p. 332, pi. lxxix, fig. 6. 



5 Edwards, 1838, Annales des Sciences Naturelles, series ii, Zoologie, vol. ix, 

 pp. 208, 238, pi. xvi, fig. 4 ; genotype C. Michelinii. 



6 i.e. with a distal bud and one lateral bud. 



