Cretaceous and Tertiary Cirr.'jyedes. IG9 



Genus Brachylepas, H. Woodward. 

 1901. Brachylepas, II. Woodward, Geol. Mag. dec. iv. vol. viii. p. loO. 



Genotype. Brachylepas naissanti, Hebert, sp. 



The genus Brachylvpas and the family lirachylepadidaj 

 were founded to embrace the sing;le species Vyryonui crelacea 

 from the B. mncronata-zowQ of Norwich, and subsec|ucntly 

 (1900, Geol. Mag. dec. v. vol. iii. pp. 339-310) Dr. Wood- 

 ward refeired to Brachylepas the species Mitella lithvtryoides, 

 Bosquet, from the Alacstnchtiau of Holland, and PoUicipes 

 jallax, Darwin, from the Upper Senonian, B. mucronata- 

 zone of Norwich. A recent paper (Withers, 1912, Geol. 

 Mag dec. v. vol. ix. p. 321) proved the identity of Brachy- 

 lepas crelacea with the valve figured by Ed. Hebert (1855, 

 ;^lem. Soc. geol. France, ser. 2, vol. v. j). 374, pi. xxix. 

 fig. 10) as Emarginula (?) naissanti, whence the name of the 

 genotype became Brachylepas naissanti, Hebert, sp. The 

 type-species was fully discussed and a restoration given 

 (reproduced, text-figure 5, p. 201). 



Now that we know tlie form, number, and disposition of 

 the valves comprising the capitulum of B. naissanti, we can 

 discuss the species Mitella Ulhotryoides and PoUicipes fallax. 

 The last-named species is dealt with under the new genus 

 Pycnolepas (^see p. 175). 



Brachylepas lithotryoides, Bosquet, sp. 



1857. Mitella lithotryoides, J. Bosquet, Notice siir quelques Cirripedes 

 receminent decouverts dans le Terrain Cretace du Duche de Lim- 

 bourg. p. 23, pi. iii. tigs. 5-10. 



1857. Mitella fallax, Darwin, sp., torn. cit. p. 21, pi. ii. figs. 8-12, 

 pi. iii. tigs. 1, 2. 



1906. Brachylepas lithotryoides, Bosquet, sp. ; II. Woodward, " Cirri- 

 pedes from the Trimmincrliam Chalk and other localities in Norfolk," 

 Geol. Mag. dec. v. vol. iii. p. 339, tigs. 1-4. 



Of Mitella lithotryoides Bosquet figured carinse, a scutum, 

 upper latus, rostrum, and a subrostrum. The subrostrum 

 and one of the carinse have at the base at least two whorls of 

 imbricating plates, of which some show exteriorly a median 

 basal notch, just as in B. naissanti. The so-called sub- 

 rostrum is evidently a rostrum, for it is wider in proportion 

 to its length than the carina, and, like the carina, has a 

 series of imbricating plates at its base ; it therefore could 

 not have served as a subrostrum. Although the presence 

 of a median basal notch in some of the imbricating plates 



