226 BULLETIN 93, UNITED STATES NATIONAL MUSEUM. 



The labrum has two stout teeth on each side of the median notch 

 (fig. 720). 



The palpi closely resemble those of B. hawaiensis 



The mandible has four rather long teeth, and a trifid lower point. 

 There are small teeth above and below the fourth tooth. The lower 

 margin bears a few long spines. There are a few hairs on the upper 

 margin (fig. 72<?). 



Cirrus i has very unequal rami of 8 and 5 segments, the anterior 

 ramus nearly twice as long as the posterior. The segments are 

 slightly convex, but not protuberant. 



Cirrus ii has ranii of 8 and 7 segments, the anterior ramus longer 

 by two segments. They are not protuberant. 



Cirrus iii is slightly longer than ii, but otherwise similar. 



Cirri iv to vi are much alike. Cirrus vi has rami of 16 segments, 

 which bear four pairs of spines (fig. 72&). 



The penis is longer than the posterior cirri, closely annulated, not 

 hairy. I see no basidorsal point. 



About 40 presumably adult individuals, besides numerous young 

 ones, are seated upon a large sea-urchin spine. From the nearly 

 uniform size of the larger barnacles, and the remains of dead ones, 

 I conclude that they are adult. They are with one or two excep- 

 tions seated with the long axis conforming to that of the spine, and 

 all but five are headed the same way. 



The species has some resemblance to the much larger B. maldiven- 

 sis Borradaile, 1 but that species, as well as all the other East Indian 

 species of Solidobalanus, has a distinct basiscutal point on the 

 tergum, while in the present form the spur is confluent with the 

 scutal margin. The low, broad ribs of the parietes are also character- 

 istic. There are fewer spines than usual on the lower border of the 

 mandible. 



Subgeniis ARMATOBALANUS Hoek. 



1913. Armato-Balanus HOEK, KifrcK/fl-Expeclitie, Monographie 31&, Cirri- 

 pedia, pp. 159, 162, 207. 



Small, conic Balani with calcareous basis; walls solid, poreless, 

 sharply and deeply costate within. Sutural septa present. Scutum 

 with the articular ridge long, tapering below, adductor ridge moder- 

 ate or subobsolete ; no crests for the lateral depressor muscle. Tergum 

 without distinct external furrow, the spur wide, occupying one-third 

 to over half the basal margin, short, the end obliquely truncated. 



1 Balanus maldivensis Borradaile, in The Fauna and Geography of the Maldive and 

 Laccadive Archipelagoes, vol. 1, 1903, p. 442, fig. 118. South Nilandu Atoll, Maldive group, 

 on a twig of wood. See also Hoek /S'i&o#a-Expeditie, Monographie, 316, p. 195, pi. 18, figs. 

 13-19. 



