66 



BULLETIN 93, UNITED STATES NATIONAL MUSEUM. 



When growing unhampered on a smooth object, this is a handsome 

 barnacle, quite distinct in appearance from B. t. coccopoma, by the 

 raised white strise of the parietes, as well as by the somewhat different 

 opercular valves. The basi-tergal corner of the scutum is less cut 

 off, and the tergal segment is less broadly deflected and less con- 

 trasted in color. The tergum has a broader spur. When crowded, 

 and sometimes under other circumstances, the shape becomes cylin- 

 dric, with deep basis, such a shape as is often assumed by forms of 

 B. tintinnabulum. Plate 14, figure 3, represents such a specimen 

 from near Santa Barbara. 



The coloration, the crowded, narrow parietal tubes, the shorter, 

 broader spur of the tergum, and the somewhat smaller size distinguish 

 it from B. t. tintinndbulum. Unfortunately, only dry specimens, 

 from which the body had been removed, are at hand. It appears 

 to be a common barnacle from Santa Barbara to San Diego, at low- 

 water mark, on rocks, oysters, shells, the carapaces of crabs, and on 

 other barnacles, having about the same distribution as B. aquila. It 

 will probably be found as far north as Monterey Bay, and may be 

 expected southward along the ocean coast of the peninsula. 



So far as is known, this is the only form of B. tintinnabulum inhab- 

 iting the Californian coast, though no doubt various oriental forms 

 are constantly brought into the deep-water ports. 



BALANUS TINTINNABULUM PENINSULARIS, new subspecies. 

 Plate 15, figs. 1 to 2d. 



Type.C&t. No. 43486, U.S.N.M. 



Type-locality. Cape St. Lucas, Lower California, growing on shells, 

 etc., collected by John Xantus. No other locality is known. 



The barnacle is cylindric or conic, with an ovate-triangular orifice. 

 Parietes cinereus, densely covered with lighter spines projecting 

 toward the base; radii from light grayish-olive to fuscous-black, paler 

 toward the rostrad edge, wide, deeply striate transversely, the sum- 

 mits level, parallel to the base. Basal edges of the septa rather thick; 

 basal pores about 18 to 21 in the rostrum. Sheath usually long, with 

 the insides of the parietes dark, the strongly oblique alse pale. 



Greatest diameter 20 mm.; height 28 mm. (type). 



Greatest diameter 22 mm; height 17 mm. (conic specimen). 



