POLLICIPES. 47 



Genus — Pollicipes. 



PoLLiciPES. Leach. Journal de Physique, torn. Ixxxv, Julius, 1817.^ 

 Lepas. Linn. Systema Naturae, 1767. 

 Anatifa. Bnigiere. Encyclop. Method, (des Vers), 1792. 

 MiTELLA. Oken. Lehrbuch der Naturgesch., 1815. 



Ramphidiona. Schumacher. Essai d'un Nouveau Syst. &c., 1817 (ante Julium). 

 PoLYLEPAS. Be Blamville. Diet, des So. Nat., 1824. 



Capitulum (secundum Klein). J. E Gray. Annals of Philos., torn, x, 2d series, 



Aug. 1825. 



VaU(B ah octodium usque ad centum et amplius. Lateribus verticelli ivferioris multis ; 

 lineis incrementl deorswn ordinatis. Subrostrum semper adest. Pedunculus squamifems. 



CHARACTERES VALVARUM IN SPECIEBUS FOSSILIBUS. 



Carina ab apice ad marghiem hasalem multum dilatata ; apex plerumque libere /»;'o- 

 minens ; pariefes a fecto non distincte separati ; linece incrementi parietum, parum obliqua. 

 Scuta p)lerumque subsolida, co7ivexa, subtrigonalia, margi?ie tergo-laterali pins minusve 

 eminente, sed noti angulo in margines duos dlscreto. 



f. Scuta, aut lavia aut lineis tenuihus incrementi solmn notata. 



A. Scuta, costd ab apice ad centrum marginis hasalis non decurrente. 



B. Scuta, costd, nonnunquam suhobsoletd, ab apice ad centrum marginis hasalis 

 decurrente. 



tf. Scuta, aut hngitudinaliter aut transverse {i. e. secundum tineas incrementi) costata. 



Valves from eighteen to above one hundred in number. Latera of the lower whorl 

 numerous, with their lines of growth directed downwards. Sub-rostrum always present. 

 Peduncle squamiferous. 



CHARACTERS OF THE VALVES IN FOSSIL SPECIES. 



Carina ; widening considerably from the apex, which projects freely, to the basal 

 margin ; parietes not distinctly separated from the tectum ; lines of growth on the 

 parietes but little oblique. Scuta generally somewhat massive, convex, sub-trigonal, with 



^ This is one of the rare cases in which, after much deliberation and with the advice of several 

 distinguished naturalists, I have departed from the rules of the British Association ; for it will be seen that 

 Mitella of Oken, and Rampliidiona of Schumacher, are both prior to Pollicipes of Leach ; yet as the latter 

 name is universally adopted throughout Europe and North America, and has been extensively used in 

 geological works, it has appeared to me to be as useless as hopeless to attempt any change. It may be 

 observed that the genus Pollicipes was originally proposed by Sir John Hill (' History of Animals,' vol. iii, 

 p. 170), in 1752, but as this was before the discovery of the binomial system, by the Rules it is absolutely 

 excluded as of any authority. In my opinion, under all these circumstances, it would be mere pedantry to 

 go back to Okcn's ' Lehrbuch der Naturgesch.' for the name Mitella, — a work little known, and displaying 

 entire ignorance regarding the Cirripedia. 



