T. H. Withers — Verruca from the Norwich Chalk. 103 



Beds, and some are typical of them. Mr, Henry Keeping concurs with 

 this conclusion at which I have arrived. Though the material is poor 

 and the fossils not well preserved like those from Harton itself, yet it 

 is probable that further search in dry weather would result in the 

 discovery of other fossiliferous horizons and enable us to fix the line 

 of separation between the Barton and Bracklesham Series in this 

 section. 



IV. — Veeuuca prisca fkom the Chalk of jS"orwich, 



By Thomas H. Withers, F.G.S. 



rpHE Cirripede Verruca prisca was first described by Bosquet (1854) 



X from the Upper Senonian and Maestrichtian of Holland and 



Belgium, and he figured detached examples of all the valves. 



Darwin (1854-5) knew of only a single example of Verruca from 

 the English Chalk, and this came from the neighbourhood of Norwich. 

 It was originally in the collection of J. de C. Sowerby, but, although 

 search has been made in the Sowerby Collection in the Geological 

 Department of the British Museum, it cannot at present be found. 

 This specimen, which was figured by Darwin (1854-5), consisted of 

 the four valves of the shell united, but without the moveable 

 opercular valves, and it was attached to a Mollusc ; Darwin thought 

 it probable that it was identical with Verruca prisca, but in the 

 absence of the opercular valves could not say so with certainty. 



Verruca prisca has been recorded by Marsson (1880) from the 

 Chalk of Biigen, but I can find no further references to the occurrence 

 of this species. 



Dr. A. W. Bowe recently submitted to me a Cirripede which 

 I considered to belong to the species V. prisca. The specimen, 

 which came from the Belemnitella mucro7iata-zone of Norwich, is 

 attached to an oyster, Ostrea semiplana, and, like the example figured 

 by Darwin, has the four valves of the shell united, the opercular 

 valves being absent. More recently Dr. Bowe sent to me, from the 

 same locality and horizon, a portion of a sea-urchin, Echinocorys 

 scutatus, to which seven examples of Verruca prisca are attached, and 

 two of these fortunately show the opercular valves in position. 



The discovery in the English Chalk of no less than eight examples 

 of this hitherto rare Cirripede is of much interest, not only because 

 they are the only known examples from the English Chalk, now that 

 Sowerby's specimen is missing, but because the presence of the 

 opercular valves has enabled me to determine definitely their identity 

 with V. prisca, Bosquet* This species, moreover, is geologically the 

 oldest known representative of the family, and, with the exception of 

 V. pusilla, Bosquet,^ of Maestrichtian age, is the only known species 

 from the Cretaceous rocks. It is certainly a remarkable circumstance 

 that we should find two perfectly complete examples of V. prisca 

 having all the valves in position, and I believe them to be the onlj^ 

 existing specimens of Cretaceous age so preserved. 



^ .J. Bosqi.iet, Notice sur quelques Cirrvpddes rdcemment decouverts dans le 

 Terr. GrAt. du Duch6 de Limbourg, 1857, p. 5, pi. i, fig. 3. 



