Cretaceous and Tertiary Cvri pedes. 175 



distinct ridge which extciicls from tlic apex to about tlie 

 middle of the scutal margin. Oa the iuiicr surface the 

 U|)[)rr cariual edge is ihit and wide, niid the inner occludent 

 edge is rounded and narrower, both edges being marked 

 with growth-lines. 



Upper latns (PI. VI F. fig. 17) a very acute-angled isosceles 

 triangle. External surlaee marked with irregularly spaced, 

 slightly undulating, trausver.se ridges, slightly upturned at 

 the lateral nu\rgins, and in the single valve seeu there arc 

 feebly marked longitudinal ridges. The growth-lines are 

 continued oa the inner surface, where they are obliquely 

 ujjturned, and meet in a raised, sharp-edged, median ridge, 

 wiiich extends to the apex. The portion marked with 

 growth-lines overlapped ti.e scuta and terga on either side, 

 the smooth triangular portion being covt red by the corium 

 or membrane lining the inside of the valves. 



Peduncular plates (PI. VIIL figs. 1-3). There are fifteen 

 examples known, and, although ot different sizes, all are of 

 the same type. They have a longitudinally ridged outer 

 wall, with from two to three prominent transverse ridges, 

 and an inwardly projecting basal ledge, on the inner extre- 

 mity of which is a deep, median, elliptical socket ; the base 

 of the inwardly projecting portion is concave. Except for 

 this socket they agree well with some peduncular plates that 

 appear to belong to the species PoUicipes glaber^ P. A. 

 Roemer. 



Pycnoh'pas fallax, Darwin, sp. 

 (PI. VII. figs. 10-14; PI. VIU. fig. 5.) 



18o0. PoUicipes nmximus, Sowerby ; R. Kner, Haidinger's Naturw. 



Abhandl. Bd. iii. Abth. 2, p. oo, pi. v. tig. 12. 

 \^^A). PoUicipes gldber, F. A. Roemer; A. Alth, Haidinger's Natunv. 



Abhaiuil. Bd. iii. Abih. 2, p. 198, pi. x. 6g. 20. 

 ? 18.5U. PoUicipes ri(jidi(s, J. de C. Sowerby; II. 13. Geinitz, Das Quader- 



.'sandsteingeijirge, p. 102, pi. ii. tigs. 8 a-c. 

 IS")]. PoUiapes fal/ax, Darwin, Pal. Soc. Mouogr. Fo3s. Lepadidffi, 



p. To, pi. iv. tig. 8. 

 1804. PoUicipes fallax, Darwin, Ray Soc. Monogr. Subclass Cirri- 



pcdia, Jialanidre, Synop. et ludex Systematicus, p. 038. 

 18o4. PolHcipes fallax, Darwin ; J. Moriis, Cat. Brit. Foss. 2nd ed. p. 96. 

 I8r)7. Mitella fallax, Darwin, sp. ; J. Bosquet, Notice sur quelques 



Cirripedes Terrain Cr^tace Ducbe de Limbourg, p. 17, pi. ii. ti-^s. 1-7 



(non pi. ii. figs. 8-12, pi. iii. tigs. 1, 2). 

 1804. PoUicipes fallax, l)i\i\7[i\ ; A. Reuss, Sitz. d. K. Akad. Wiss. 



Wien. vol. xlix. Ab'b. i. p. 240, pi. iii. figs. 1-6 (? non titrs. 12-15). 

 1877. PoUicipes fallax, Vnrw'm; II. Woodward, Brit, Mus!^ Cat. Brit. 



Foss. Crustaiea, p. 140. 

 1880. I'oUicipes fallax, l^avx^'m; Th. Marsson, Mittheil. naturw. Ver. 



>seu-Vorpunuiiciu und Riigen, xii. p. 20 (nou pi. ii. iig. 0). 



