502 W. D. Lang — Cretaceous Cheilostome Polyzoa. 



IV. Mystriopora, 1 new genus. 



In 1846 2 Reuss described two uniserial Cheilostornes from the 

 Cenomanian of Bohemia. One of these, Escharina dispersa, Reuss, 

 has been already dealt with and renamed Dacryopora reussi. 3 The 

 other, Escharina perforata, Reuss, apparently agrees genetically with 

 a form washed from the Chalk Marl of Cambridge by the late Mr. F. 

 Mockler. It cannot remain in the genus Escharina 4, which was 

 founded by Edwards for twenty-eight recent species differing 

 altogether from the form under consideration. It is therefore here 

 placed provisionally with the Chalk Marl specimen from Cambridge, 

 which is the genotype of a new genus, Mystriopora. 



Diagnosis. Incrusting, pauciserial Cheilostome Polyzoa with early 

 uniserial stages, and with bilateral to unilateral branching ; zocecia 

 dimorphic ; normal zooecia oval or slightly pyriform with very short 

 caudse or with no caudae ; termen with spines ; extra- terminal front 

 wall well developed proximally ; intra-terniinal front wall a very 

 small bevel ; aperture oval ; avicularia small, often a pair placed 

 laterally and distally to each aperture. 



Genotype. Mystriopora mockleri, n.sp. 



Distribution. Cenomanian. 



Key to the genus Mystriopora. 



fA. Avicularia rare, without sharp points ; zoarium largely uniserial. 



1. M. perforata (Eeuss). 

 "j B. Avicularia frequent, sharply pointed ; zoarium largely pauciserial. 

 I 2. M. mockleri, n.sp. 



Mystriopora. mockleri, n.sp. PI. XVII, fig. 7. 



Diagnosis. Mystriopora in which the pauciserial habit is soon 

 attained and the avicularia are numerous and sharply pointed. 



Type-specimen. British Museum specimen D. 21670. P. Mockler 

 Coll. 



Distribution. Cenomanian, base of Chalk Marl, N.E. of Cambridge. 



V. Distelopora, 5 new genus. 



Among the material washed by the late Mr. F. Mockler from the 

 Chalk Marl of Cambridge are several specimens of an incrusting 

 Cheilostome, uniserial in its early stages and differing from previously 

 described Cretaceous forms ; the following is a diagnosis : 



Diagnosis. Incrusting multiserial Cheilostome Polyzoa with 

 unilateral branching, but with early uniserial stages with bilateral 

 branching ; zooecia monomorphic, oval with no caudse ; termen with 

 eight spines of which the proximal pair are widely separate from the 

 distal three pairs and much larger than them ; extra-terminal front 

 wall wide laterally and proximally ; intra-terminal front wall laterally 

 and proximally is a wide bevel or narrow lamina ; aperture ovate to 

 elliptical, somewhat constricted laterally. 



1 t6 fxvffrptov, ' a spoon ' ; the normal zooecia resemble the bowl of a spoon. 



2 Eeuss, 1846, Verstein. bohm. kreideform ; part 2, pp. 67-8. 



3 Lang, 1914, op. cit., p. 443. 



4 Edwards in Lamarck, 1836, "Hist. Nat. Animaux sans Vertebres," 

 2nd edition, vol. ii, p. 230. 



5 Si- prefix meaning ' two ' and y (TttjAtj ' a post ' . 



