62 



BULLETIN 



UNITED STATES NATIONAL MUSEUM. 



Scutum with simple growth-ridges, at least in young individuals; 

 adductor ridge very weakly developed. Tergum rather long, with 

 relatively sliort spur, separated by nearly twice its own width from 

 the basoscutal angle, the basal margin sloping to it on both sides. 



Carinorostral diameter 27 mm.; height 20 mm. (type). 



Carinorostral diameter 21 mm.; height 25 mm. (cylindric speci- 

 men). 



Carinorostral diameter 41 mm.; height 49 mm. 



More brilliant than other oriental forms of the species; by its 

 beautiful color and smoothness resembling B. t. coccopoma, and 

 readily distinguishable from other Indo-Pacific races of B. tintinnabu- 

 lum. Unfortunately, the large individuals had lost their opercular 

 valves, which were described from one of the small individuals of a 

 group of over 20, from Wakanoura. 



Large specimens become quite heavy and strong, and I had, at one 

 time, some suspicion that the race might be referable to B. ajax 

 Darwin; but a comparison with Darwin's description and a specimen 

 of that species from Mariveles, Luzon, assures me of their specific 

 difference. The very large rostrum, dark-colored sheath, small 

 orifice, and remarkably thick walls of B. ajax are conspicuous dif- 

 ferential characters. 



BALANUS TINTINNABULUM AZORICUS, new subspecies. 

 Plate 12, figs. 2, 2a, 21. 



Type -Cat. No. 4S126, U.S.N.M., from Crace, Terciera, Azores, 

 growing on Patella ccerulea; taken in 1894; collector not recorded. 



The barnacle is cylindric in general shape, the orifice rather large, 

 ovate-trigonal. Parietes roughened by numerous small, irregular 

 riblets. Summits of the radii level. Color dull blue- violet or dark 

 hyssop-violet, clouded with white; terga pale yellow externally; 

 scuta marked with the darker shade down the middle and internally. 

 The sheath is pale violaceous with dirty whitish also; carinolateral 

 compartments sometimes paler than the others. Height 40 mm.; 

 diameter 29 mm. 



Scutum rather flat, the tergal segment but slightly deflected; 

 growth-ridges narrow and prominent, conspicuously crimped, intervals 

 deeply striate. Adductor ridge strong and acute, much as in B. t. 

 concinnus. 



