62 



Br. J. W. Gregory — Some Jurassic Bryozoa. 



Eippotlwa. Phillips' figure is quite useless ; but, with his usual 

 courtesy, Mr. H. M. Platnauer has kindly lent me the type 

 •which is now in the York Museum ; the species, however, certainly 

 does not belong to Hippothoa as that genus is now defined. 



In a paper on the British Paleogene Bryozoa^ I pointed out the 

 occurrence of Onychocella in the Jurassic, and, considering the rarity 

 of known species of Chilostomata of this age, I take this opportunity, 

 with the kind permission of Dr. Woodward, of describing this species 

 and one of the genus Memhranipora, Both specimens are in the 

 British Museum. 



Order: CHEILOSTOMATA. 

 Suborder: ATHYEIATA. 



Family : Membraniporid^. 



Genus : Mkmbranipora, Blainville, 1834. 



Species I. : Membranipora jurassica,^ n. sp. (Fig. 1). 



Diagnosis. 



Zoarium : Erect, foliaceous, bilaminate. 



Zooecia : Eegularly quincuncial, form hexagonal, slightly irregular. 

 Opesia very large. Aperture occupying the whole of the opesium 

 and markedly clithridiate in shape. Rim apparently plain, highest 



on the margin of the aperture, and sloping thence to the inter- 

 zocecial sutures. Front wall very small in extent, consisting only 

 of a narrow space at the upper end of the zooecium, sometimes re- 

 placed by ooecium. 



OcBcium : Cucullate, reniform in shape, surrounded by a low rim. 

 The ooecia are sparsely scattered over the zoarium. 



Avicularia : Usually a pair at the upper corners of the zooecium, 



1 Trans. Zool. Soc. London, vol. xiii. pt. vi. 1893, p. 239. 



2 So named as it is the first recorded Jurassic species of this genus and family. 



