of the British Jurassic Bryozoa. 295 



Hetoropora calyclnn, Bruder, 1881, Jiirabl. St.n-uberj^, Sitz. k. Akad. 



Wiss. Wieu, Bd. Ixxxiii. Abl. i. p. 89, pi. ii. fig-. 6. 

 HHeropora ficulina, Michelin, 1846, op. cit. p. :244, pi. Ivii. fig. 2. 

 Polytrenia ficulina, d'Orbigay, 1849, Prod. Pal. t. i. p. 323. 

 Reptomulticrescis ficulina, d'Orbigny, 1852, op. cit. t. v. p. 1079. 



Diagnoshf. — Zoarium of erect branches, which are gene- 

 rally cylindrical and either grow in irregular stumpy branches 

 (typical form), or expand into thick pyriform masses (form 

 pyriformis), or into lobed yl/cj/ortiwm-shaped masses (var. 

 ficulina)^ or regular cylindrical branches (var. ramosa). The 

 branches dichotomose and may sometimes anastomose (form 

 reticulata). The surface is level. 



Zocecia crowded. Diaphragms numerous. Mesopores 

 irregular in distribution. Frequently only at the angles 

 between 2ooecia, but sometimes completely surrounding them. 



Distribution. — Eno'land : Inferior Oolite and Grreat 



• ... 



Oolite. Foreign : Bajocian and Bathonian, France and 

 Germany ; Callovian, France and Austria. 



2. Heteropora Jaminata, sp. n. 



Diagnosis. — Zoarium encrusting, growing in layers supsr- 

 posed into thick masses. The surface of the zoarium is 

 level. 



Mesopores irregular in distribution, generally numerous. 



Distribution. — Inferior Oolite, Dorset ; Bradford Clay, 

 Wiltshire. 



Affinities. — This species differs from H. conifer a mainly by 

 zoarial characters, though the mesopores are generally more 

 numerous. The fact that the mesopores are useless as specific 

 guides is shown by their great variation in diflferent parts of 

 the same specimen of species of this genus. This shows that 

 Haime was correct as to the variability in the number of these 

 structures, though, by his refusal to admit any value to their 

 complete absence, he underrated their significance. 



3. Heteropora oviformis, sp. n. 



Diagnosis. — Zoarium small, free, ovate masses. 

 Zocecia short. Surface of zoarium covered with large 

 scattered pustules. 



Distribution. — Bradford Clay, Bradford, Wiltshire. 



21^ 



