C0R0NULA BALiENARIS. a 415 



1. CORONULA BAL^NARIS. PI. 15, fig. 2, 2 b : PL 16, 



fig. 3, 5. 



Lepas bal^nams. Gmelin. Systeraa Naturae (1789). 



— — Chemnitz. Conch., vol. 8, Tab. 99, fig. 845, 



846 (1785). 

 Balanus — Bruguiere. Encyclop. Method., PI. 164, fig. 13 — 



18 (1789). 

 Cokonula — Lamarck, Annales du Museum, vol. 1, Tab. 30, 



fig. 2—4 (1802). 



— — Chenu. Illust. Couch., Plate, fig. 1 and 4. 



— — Be Blainville. Diet, des Scien. Nat., 1818 and 



1824, Tab. 117, fig. 3,3 a. 



Shell much depressed, with longitudinal flattened ribs, 

 having simple edges ; orifice rounded-hexagonal : radii very 

 thick, almost equalling the shell in thickness : opercular 

 valves four, 



Hab. — Attached to whales in the Southern Ocean. 



Having described, under the genus, in so much detail 

 the structure of the whole shell, it will be sufficient here to 

 point out the characters by which this species differs from 

 the others. 



General Appearance. — The shell is generally much depressed, though 

 sometimes, in large specimens, from the turning in of the basal edges, a 

 considerable degree of convexity is acquired. The radii are moderately 

 wide, and give a star-like appearance to the shell. The surface of the 

 whole upper part of the shell is smooth ; the broad and much flattened 

 ribs («*. e. the terminal, transverse loops of the folded walls) of which 

 each compartment is formed, generally clivide at a short distance from 

 the apex. The close sutures separating these ribs are straight, and not 

 finely serrated, by which character alone this species can at once be 

 discriminated from the others. The surface, when closely examined, 

 is found to be finely striated longitudinally, and is transversely crossed, 

 chiefly in the lower part, by minutely beaded growth-ridges. The 

 orifice is rounded-hexagonal, and is small compared with the whole 

 shell ; it is also smaller than the basal edge of the internal cavity of 

 the shell ; consequently the whole basal edge cannot be seen through 

 the orifice from one point of view, — the operculum of course having 

 been removed. An unusually large specimen was 2*75 of an inch in 



