276 



BULLETIN 93, UNITED STATES NATIONAL MUSEUM. 



Diameter 48 mm. ; height 19 mm. 



Diameter 53 mm. ; height 13 mm. 



By its depressed contour and the flattened ribs of the upper sur- 

 face this species has a superficial resemblance to B. complanaiaj 

 but the narrow radii with a large cavity under them, the crenulated 

 edges of the terminal flanges of the ribs, and their irregular branch- 

 ing, and especially the shape of the body chamber, are characters 

 certainly allying it to C '. diadema. The sculpture is remarkably 

 delicate. From one-fourth to one-third of the whole diameter is 

 embedded in the skin of the whale, so that the barnacle projects very 

 little. The oral opening has a " hood " as in B. diadema,. 



It was supposed by Darwin to be a Pacific species, but the only 

 definite locality he had was Iquique, Peru, on Mr. Cuming's author- 

 ity. Mr. Gruvel gives the locality Chonos Archipelago, Chile, for a 

 single example in the Paris Museum. It occurs on the lip and per- 

 haps other parts of the whale where the skin is thin and light 

 colored. It appears to be perfectly distinct from both of the old 

 species. About 20 specimens seen. 



CORONTJLA COMPLANATA (Morch). 



Plate 63, figs. 1, 2, 3, 3a. 



1790. Lepas balcnaris SPENGLEK, Skrivter af Naturhistorie-Selskabet, vol. 



1, p. 187. 

 1802. ? Coronula balcenaris DUFKESNE, Annales clu Museum Nationale, vol. 



1, p. 473, pi. 30, figs. 2-4. 1 



1818. Cetopirus baJcenaris RANZANI, Opuscoli Scientific!, vol. 2, p. 87. 

 1818. Coronula balamaris LAMAECK, Hist. Nat. ties Animaux sans Vertebres, 



vol. 5, p. 387. 



1823. ? Lepas quwquevalvis MAWE, The Linnsean System of Conchology, 

 p. 5, pi. 2, fig. 3. 2 



1824. Coronula balanaruin BLAINVILLE, Dictionaire cles Sciences Naturelles, 

 vol. 32, p. 380 (obvious error for 



1 It is quite possible that the figures publisher! by Dufresne as C. balwnaris arc really 

 C. reyince ; but their identity would have no effect upon nomenclature. 



2 I have been unable to decide whether Lepas quinquevalvis Mawe is C. complanata or 

 C. regin<e, as the upper view, when partly covered with the whale's skin, shows no clearly 

 diagnostic features in the drawing. The specific name must be dropped SIM indeterminate. 

 This individual and a specimen of Chelontbia testiidinaria mentioned by Darwin (Mono- 

 graph, p. 384, footnote) are the only cases I have seen recorded of the abortion of one 

 compartment in any sessile barnacle. They seem singularly exempt from meristic varia- 

 tions. 



