the Cirripede Subgenus Scilltelepas. 263 



trustworthy evidence, then the species, P. ooUticus and 

 P. aaJeusis^, P. quenstedh\ and P. (?) lot/iariii(/icusf, Mdciiiii, 

 all of wliicli have valves siniihir to S. gaoei/i, are [)robably 

 nearly related, and belong to Scilhflepas. 



Against this view is tlie fact that Darwin has described 

 and figured in his Monogranh (p. 52, pi. iii. fig. 2 /») a com- 

 paratively large rostrum of P. ooUticus, similar to but rather 

 wider than the carina. I am not at all sure, however, that 

 in this particular Darwin has allowed sufficiently for varia- 

 tion, and that the valve really is a rather wide carina ; a view 

 of the inner surface of the valve would have decided tlie 

 matter. 



Zittel has referred the species P. quemttedti to his genus 

 Archceolepas, but the valves appear to differ in structure from 

 the valves in Archci'olepas, and this view is strengthened bv 

 the fact that there is among the valves of P. quenstedii 

 figured by Max Schlosser (1881) | a rostrum which agrees 

 ninch more with the rostrum of Scilhelepas, being decidedly- 

 different in shape from the rostrum in undoubted species of 

 Archeolepas. 



Altogether the evidence, while not conclusive, is in favour 

 of referring S. gaveyi to Scillcelepas, and it is clear that there 

 is no indication of its affinity with Pollicipes. I am inclined 

 to think that further material will show this species, together 

 with Pollicipes ooliticus, P. aalensis, P. quenstedti, P. (?) 

 lotharingicun, and probably one or two other Jurassic species, 

 to belong to Scillcelepas, or, at least, to a genus nearly related 

 tliercti). 



Comparison loith other Species. — Pollicipes (?) lotharingicus, 

 M^chin, from the spinatus-zone of Agincourt (Meurthe-et- 

 Moselle), France, is the only other species known from the 

 Pliensbachian, although it occurs at a somewhat highor 

 horizon than S. gavegi. Only a single carina antl tv-rgum 

 are known ; the carina appears to be much more attenuati-d 

 and ta|)eri ng than S. gavegi ; the tergiim differs in its pii - 

 portions, having a shorter ocoludent margin, which makes a 

 larger angle with the carinal margin, and the scutal margin 

 is proportionally much longer, and the angles formed by the 

 zones of growlli appear to have their apices much nearer to 

 the carinal margin. Moreover, the valves do not ajipear to 

 be niaiked with longitudinal lines, since no mention is miuhi 

 of them in the description, and nothing is said of the fiuj 



♦ Richardson, T.., 1908, Geol. Mag. dec. v. vol. v. p. 3'i-2, toxt-fi<r. ; 

 Withers, T. II., lull, Proc. Cotteswold Xtit. F. C. vol.xvii. pt.ii. p. L'7n. 



t Mechin, A., 1901, Hull. Soc. Sci. Nancy, scr. :^, vol. ii. fasc. i. p. 1(5, pi. 



J Schlosser, Mux, 1881, ' Pnlceontojjrapliica,' l!d. xxviii. p. CO, pi. viii. 

 fig. 8. 



