T. II. Withers — The Cirripede Brachylepas crefacea. 321 



VII. — The CiERiPEDE '■Brachylepas cbetacea\ H. Woodward. 



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



(PLATE XX.i) 



AMONG the fossil Cirripeclia the species ' Brachylepas cretacea ' is 

 of extreme interest, since it affords an important connecting- 

 link between the pedunculate and sessile forms. Records of its 

 geographical distribution, moreover, show it to have an exceedingly 

 wide range, but up to the present its vertical range appears to be 

 restricted to the zone of Belemnitella mncronata in the Upper Senonian. 

 "We owe our knowledge of Brachylepas to Dr. H. Woodward, F.R.S., 

 who in 1868 founded the species B. cretacea on a single valve under 

 the genus Pyrgoma, and in 1901 on a further and more complete 

 specimen established the genus Brachylepas and the family Brachy- 

 lepadidfe. Attention is now drawn to this species mainly on account 

 of the fortunate iind of the remaining valves of the capitulum. 



In a work on the fossils of the Chalk of Meudon, Ed. Hebert (1855) 

 described and figured what now appears to be a valve of Brachylepas 

 cretacea, under the name Emarginulai^.') Naissanti. J. Boehm (1906) 

 called attention to this figure, and considered that it was distinguished 

 from B. cretacea only by its smaller size, and that, should further 

 research show that in it we had a young stage of B. cretacea, then 

 this form, so widely though sparsely distributed in the Baltic Chalk, 

 would be denoted as B. Naissanti, Hebert, sp. 



Before seeing Boehm's note I had already formed the opinion that 

 the specimen iigured by Hebert as Einargmula (?) Naissanti was the 

 same species as Brachylepas cretacea, H. Woodward. In response to 

 an application from the Geological Department of the British Museum, 

 search for Hebert's type-specimen was most kindly made by the 

 Director of the Museum National d'Histoire Naturelle, Paris, by 

 Professor Emil Haug of the Sorbonne, and Mr. Leon Bertrand of the 

 Ecole Normale, where most of Hebert's earlier type-specimens are 

 preserved. The specimen, however, could not be found and, as 

 Professor Haug writes, has probably been lost. Portunately Hebert's 

 figure is quite good and readily recognizable. Moreover, it is so like 

 the figure of Pollicipes cancellatus given by Marsson (1880), which 

 Dr. H. "Woodward (1906, p. 338) said was undoubtedly the same 

 as his B. cretacea, that they might even serve for figures of the 

 same specimen ; and the identity of the two latter species is fully 

 borne out by an examination of their type material. The three type- 

 specimens therefore must be referred to a single species under the 

 name B. Naissanti, Hebert, sp. 



History. — The earliest record of this species appears to be that given by 

 Nilsson (1827) who figured a valve from the Chalk of Scania as ' ' maxilla 

 inferior . . . Belemnitce mamviillati^\ This opinion was held because 

 these valves were found always in association with Belermiites mammillatus 

 {= B . subventricosus) . 



Ed. Hebert (1855) thinking that a valve found in the Chalk of Meudon was 

 a portion of an Emarginuloid shell, described and figured it as Emarginula (?) 

 Naissanti. 



^ Plate XX will appear with the second part of this paper in August. 

 DECADE V. — VOL. IX. — NO. VII. 21 



