THE 



GEOLOGICAL MAGAZINE. 



NEW SERIES. DECADE V. VOL. VI. 

 No. VIII. — AUGUST, 1909. 



I 



OJElXC3rXl<T.A.JL. .A^IRTICLES. 



I.— Notes on new ok iMPEEFECTLr known Chalk Polyzoa. 

 By E. M. Brydone, F.G.S. 

 (PLATE XIV.) 

 N these notes it is my object to describe and figure some of the more 

 important Chalk Polyzoa that have not yet been described, or 

 have been described from material less complete than mine. 



Genus HOMALOSTEGA, Marss. 

 This genus has been dismembered bv Canu,^ who distributed the 

 specie^ grouped under it by Marsson among various genera of his 

 l)iplodermiata ; but they all appear to belong to his Monodermiata and 

 have enough m common to justify the retention of a most convenient 

 genus. 



HoMALosTEGA ANGLicA, nov. PI. XIV, Fio-s. 1 and 2. 



Zoarmm always adherent, growing strongly in all directions 



Zocemm very tumid ; aperture subterminal, subtriangular, sides 

 very faintly mflexed, lower lip very faintly curved inwards and bearing 

 a well-marked raised rim, deep slits at the corners. 



Avicularia accessory, abundant, laterally symmetrical ; they some- 

 times remain rudimentary in the mature stages 

 of the zoarium (Fig. 2), but normally they 

 become half as long as the zooecia, round below 

 and tapering gradually upwards to a point, with 

 a small arrowhead-shaped aperture into which 

 project two denticles which are rarely preserved. 

 They lie almost always with their long axes 

 approximately parallel to the lines of growth. 



Ocecia unknown, unless occasional inflations of Homalostega anglica. 

 the upper lip of the aperture and the front Avicularium highly 

 wall adjoining it are ooecial in nature. Very magnified, 



abundant at Trimmingham, where, and at Norwich and Sherringham, 

 I recorded it m en-or as H. pavonia, Hag. sp., from which, judging 



1 " Eevision des Bryozoaires du Cretace figures par D'Orbigny " : Bull. Soc. Geol. 

 France, 1900, p. 338 et seq. >=> r o j 



DECADE V. — VOL. VI. — NO. YIII. 22 



