of the British Jurassic Bryozoa. 289 



2. Actinopora diplopora (Branco), 1879. 



Defrancia diplopora, Branco, 1879, Unt. Dogg. deut. Lothr., Abh. geol. 



Specialk. Els.-Lothr. Bd. ii. Heft i. p. 131, pi. vi. fig 9. 

 Ac(ino2)ora diplopora, Friren, 1893, Bry. ool. inf. Metz, Bull. Soc. hist. 



nat. Metz, s^r. 2, t. vi. p. 57. 



Diagnosis. — Zoarium large and thin ; several zoaria often 

 grow together into a semiconfluent incrustation : the ridges are 

 from 35 to 50 in number ; they are very thin, irregular, and 

 high, and extend to the margin of the zoarium ; they some- 

 times branch. No peripheral selvage. In some zoaria (var. 

 alia) the ridges are almost as high as the zoarium is broad, 

 and the central depressions are accordingly very deep. 



Distribution. — England : Inferior Oolite — Great Oolite. 

 Foreign : Bajocian, Germany. 



Genus 2. KoLOLOPHOS, gen. nov. 



Constellaria, Haime, 1854 (non Dana, 1848). 

 Radiopora, pars, Pictet, 1857 (non d'Orbigny, 1852). 



Diagnosis. — Theonoidge in which the zoarium consists of 

 flat encrusting sheets formed of numerous radial groups of 

 zocecia. The radial ridges are broken up into groups, the 

 arrangement of which is irregularly linear. 



Type species : Kololophos Terquemi {YiQAxno). 



Affinities. — The type species of this genus was referred 

 by Haime to Dana's genus Constellaria, which at that time 

 was misunderstood. The American fossil has recently been 

 redescribed by Ulrich * ; it is quite different from this species. 

 There is a certain superficial resemblance, due to the pi'omi- 

 nence of radial non-poriferous lines ; but in Constellaria 

 these lines are solid (" maculae " of Ulrich) and in Kololophos 

 they are depressions between zocecial ridges. 



The nearest ally of this genus is Actinopora ; from this it 

 differs by the confluence of several radial groups into one 

 sheet and the broken interrupted character of the ridges. 



1. Kololophos Terquemi (Haime), 1854. 



Constellaria Terquemi, Haime, 1854, Bry, Jur., M^in. Soc. geol. 



France, s^r. 2, t. v. p. 207, pi. x. fig. 6. 

 Radiopora Terquemi, Pictet, 1857, Traits Pal. ed. 2, t. iv. p. 153. 



Diagnosis. — Zoarium formed of several confluent disks. 



• E. 0. Ulrich, " PaU-eont. Illinois.— Palaeozoic Bryozoa," Geol. Surv. 

 111. vol. viii. pt. ii. sect. vi. 1890, p. 374. 



