40 FOSSIL CIRRIPEDIA. 



resembles C. balcenaris, and differs from C. diadema. The lower edge of the sheath does 

 not seem to have projected freely, — in this respect, also, resembling C. balcenaris. From 

 the basal margin of the alas not being narrow, and from the inner ends of the folded walls 

 being, as it would appear, also broad, I have little doubt that the cavity in which the 

 animal's body was lodged, resembled in shape that in C. balcenaris, the membranous basis 

 being larger than the orifice of the shell. 



Opercular valves unknown. 



Summary. — This species is more nearly related to C. diadema than to the others ; but 

 in some points, just specified, it resembles C. balcenaris. The characters by which it 

 differs from all the species are, firstly, the more prominent transverse ridges on the 

 external surface of the shell, and more especially on the surfaces bounding the outer sides 

 of the cavities occupied by the epidermis of the whale. Secondly, the character of the 

 teeth, or rather ridges, along the lines of junction between the transverse loops. And, 

 thirdly, the spaces between the radii and the special plates on which the alse rest, being 

 solidly filled up. 



The Coronula bifida is an Italian tertiary species, so named by Bronn, in his " Italiens 

 Tertiar-Gebilde" (1831), p. 126. It is very possible that this may be identical with 

 C. barbara, but Bronn does not seem to have been aware of the absolute necessity of 

 giving minute details in his descriptions of fossil cirripedes. The chief character of 

 C. bifida is thus given : — " Eine tiefe Furcle oder Spalte theilt die Langenrippe von oben 

 herab bis zur Halfte, welche bei der sonst ahnlichen C. diadema entweder ganz fehlt, oder nur 

 zuweilen kurz angedeutet ist." Had it been stated that the longitudinal ribs were divided 

 from the middle down to the base, instead of from the top to the middle, the description 

 would have been intelligible to me, though the character thus afforded would not have 

 been of specific value, as this dividing of the ribs occasionally occurs in all four species, 

 and is produced by the formation of new folds in the walls. 



Family — Verrucid^e. 



Cirripedia sine pedunculo : scuta et terga, musculis depressoribus non instructa, ex uno 

 latere tantum mobilia, ex altero cum carina et rostro in testam asymmetricam immobiliter 

 conjunct a. 



Cirripedia without a peduncle : scuta and terga, not furnished with depressor muscles, 

 moveable only on one side, on the other side united immoveably with the rostrum and 

 carina into an un symmetrical shell. 



