] 04 T. H. WitJters — Verruca from the Norwich Chalk. 



Family VEKRUCID^, Darwin. 



Sessile, asymmetrical barnacles, in wliich the shell is composed of 

 six valves, namely, the rostrum, carina, a scutum, and a tergum, all 

 much modified in shape and immoveably interlocked to form the wall, 

 and a single scutum aud tergum which are moveable and form the 

 lid-like top. 



The family consists only of the single genus Verruca. . 



Genus Verrtjca, Schumacher. 

 Most of the species of this genus are known by one, or very 

 few examples only, so that very little can be said of the variability 

 in the individuals of a species. This is especially the case with 

 the recent deep-sea forms, which appear to be more nearly related to 

 the Cretaceous species. It appears to be quite a matter of chance 

 whether the right- or the left-hand scutum and tergum are modified 

 to interlock and form the wall with the rostrum and carina, so that 

 individuals of any species may occur with the moveable opercular 

 valves on either the right or the left side. 



Verruca prisca, J. Bosquet. 



1854. Verruca pyiscci, J. Bosquet, Les Crust. Foss. du Terr. Cretace clu 



Duche de Limbourg, p. 14, pi. i, 

 tigs. 1-7, 7'. 



18-54. ., ., C. R.Darwin, Eay Soc. Monogr. Sub-class 



Cirripedia, Balanidse and Verrucidse, 

 p. 525, pi. xxi, tig. 4, and Synopsis et 

 Index Systematicus, p. 626. 



185o. ,, ., C. E. Darwin, Pal. Soc. Monogr. Foss. 



Balanidffi and Verrucidte, p. 43, pi. ii, 

 tigs. 10«-c. 



1857. ., .. J. Bosquet, Notice surquelquesCirripedes 



recemment decouverts dans le Terr. 

 Cretace du Duche de Limbourg, p. 4, 

 pi. i, figs. 2a~h. 



1877. .. ., H. Woodward, Brit. Mus. Cat. Brit. 



Foss. Crustacea, p. 144. 



1880. ,, ., Th. Marsson, " Cirrip. d. Weiss. 



Schreibkreide d. Insel Riigen " : 

 Mittheil. naturwiss. Vereine von Neu- 

 Vorpommern und Riigen, Jahrg. xii, 

 p. 25. 



1912. Vemica stceiistrupi,^ K. B. Nielsen, " Cirripedierne i Danmarks 



Danien-Aflej ringer " : Meddel. Dansk 

 Geol. Forening, Bd. iv, Hft. i, p. 39, 

 pi. i, figs. 25, 26. 



Specific Characters. — Shell elevated, smooth ; lower articular ridge 

 of moveable scutum broader than the upper articular ridge. 



■" Seven examples of Verruca from the Bryozoa Limestone (Danian) of Faxe, 

 Denmark, have been recently described by Mr. K. Briinnich Nielsen under the 

 new name V. steenstriqn. All the specimens are attached to the inside of tlie 

 cup of the sessile Crinoid Cyathidium 1iolopi(S, and have the four valves of 

 the sliell united, but no examples of the moveable opercular valves have been 

 found with them. To judge from the description and figures, there seems 

 little doubt that they are identical with V. pi-isca, Bosquet. 



