Cretaceous and Ttrtiary Cirripedes. 179 



Norwich iMuseuni (21 5G 6) measurinjr 2.'2'1 mm. in lenirth 

 and 7 4 mm. in breadth. Tliese measurements, however, 

 are exceeded by two valves in the Geological Department of 

 the British iMuseiim, said to be (II. Woodward, 1906, |). 3il) 

 prohaljly from the Oher Quader of Plauen, near Dresden. 

 They arc : — 



Length. Breadth, 

 mm. mm. 



Scutum (I. 14050) 20-2 107 



Tergum (I. 140o2) 231 100 



Description of valves. In this species the valves are mode- 

 rately thick and conspicuously marked externally with ra-her 

 wide, prominent, transverse ridges, which terminate each 

 zone of growth, but the valves are not ridged longitudinally, 

 or at least only weakly so. The transverse ridges are more 

 l)romineut at the occludcnt margins of the scuta and terga 

 and on the lateral margins of the other valves. 



Carina (PI. VII. fig. 14) semicylindrical, slightly or 

 moderately bowed inwards, strongly convex trausveisely, 

 not carinate ; basal margin somewhat concave. Outer sur- 

 face ornamented with a number of strong but somewhat 

 flattened ridges, which are sometimes fairly regularly 

 spaced, but more often irregularly spaced. The apical half 

 of the valve projected freely, and on the inner surface 

 the freely projecting portion is marked with growth-lines 

 which extend from the basal angles and meet in a flatly 

 rounded angle below the apex. 



Rust rum (PI. VII. fig. 10) semicouical, smaller and propor- 

 tionally wider than the carina, usually considerably bowed 

 inwards, strongly convex transversely, with a median keel 

 feebly marked in some speiimens, but not apparent in 

 others; basal margin concave. Ornamented externally like 

 the carina. The valve projected freely to nearly half of its 

 extent, and on the inner surface this portion is mai ked with 

 growth-lines, which extend from the basal angles, and on 

 reaching about half the length of the valve tuni abruptly 

 inwards and downwards, and meet in a concave curve below 

 the ai)ex. 



Scutum (PI. 11. fig. VII) elongately triangular, with the 

 basi-lateral portion slightly produced, moderately convex 

 transversely, apex acuminate and strongly bowed towards 

 the terga ; occludent margin strongly convex ; basal margin 

 nearly straight, and at the rostral angle making almost a 

 right angle with the lower part of the occludent margin ; 



