THE 



GEOLOGICAL MAGAZINE. 



NEW SERIES. DECADE IV. VOL. VIII. 

 No. IV.— APRIL, 190L 



I. On ' PvHGOilA CRETACEA,'' A CiRRIPEDE, FKOM THE TJPl'KK 



CiiALK OF Norwich and Makg.\te. 



By Hexky AVoomvARD, LL.D., F.E.S., V.P.Z.S., F.G.S. 



(PLATE VIII, Fics. 1-,).) 



IN the year 18G5 I noticed the occurrence of what appeared to be 

 a sessile Cirripede from the Upper Chalk of Norwich, and 

 referred it to Leach's genus Pijrgoma. For this unique example the 

 name of Pyrgoma cretacea was then proposed/ and afterwards, in 

 1868, it was more fully described and figured by me in the 

 Geological Magazine.- I also pointed out that Charles Darwin, 

 in bis Monograph on the Fossil Cirrepedia,' had described a fossil 

 form belonging to this genus under the name of Pijnjoma anglicum, 

 from the Coralline Crag of Ramsholt, Sufiolk, a species found living 

 off the south coast of England and of Ireland, Sicily, Madeira, Cape 

 de V^erde Islands, etc. ; while Michelotti had named, but not 

 described, a species (^Pyrgoma iindata) from the North Italian 

 Tertiary strata. 



The only other form of sessile Cirripede known, which extends 

 back in time to the Chalk formation, is the genus Verruca, which 

 M. Bosquet of Maestricht first described in 185o from the Chalk of 

 Limbourg under the name of Verruca prisca.* This species was 

 likewise discovered by J. de C. Sowerby in the Upper Chalk of 

 Norwich, and described under the same name by Charles Darwin.'' 

 Like the genus Pyrgoma, Verruca occurs fossil (Verruca StrOmia) in 

 the Glacial beds of Scotland, the Ked and Coralline Crag of Suffolk, 

 and recent on the shores of Great Britain and Ireland, etc. 



' Brit. Assoc. Birmiiigli;ini (18U.3), Reports, p. 321. 

 ^ Geot.. Mag., Dec. I. Vol. V (1868), pp. 258-9, PI. XIV, Fi?:s. 1, 2. 

 =* " The Fossil Balanick- aud Verrucithe " : Pal. Soc, 1854, p. 30, tab. ii, liir. 7. 

 * J. Bosquet: " Mou. Crustaccs toss. terr. Cret. Diiche de Liinbourj,'."' p. 14, 

 fii^s. 1-7. Darwin makes a distinct family for this c^emis— the Vkku ucid.v;. 

 ^^ Men. Pal. Soc, 18.54, p. 43, tab. ii, ds;. 10. 



nECAUE IV. — VOL. VIII. — NO. IV. !<• 



