THE SESSILE BARNACLES. 



99 



pores near the periphery, at least in places, but is in great part pore- 

 less. Central portion is thin. 



Carinorostral length of tha base 31 mm,; width 28.5 nun.; height 

 23 mm. Length of the scutum 10.5 mm. ; width 5 mm. Length of 

 the tergum 8 mm.; width 5 mm. 



The labrum has two teeth on each side of the median cleft. Palpi 

 having a distal group of long spines externally. Inside there is a 



Fig. 24.— Balanus amphitrite peruvianus. a, labrum. 6, anterior part of 8th segment of cirrus 



III. C, anterior part of an intermediate segment OFCIRRUSVI. d, outside of palpus, e, MAXILLA. 

 /, MANDIBLE. 



long area of short spines, part of them curved or hooked, and a 

 distal tuft of longer spines. It is similar to B. amphiirite niveus (fig. 

 21a) in arrangement of the spines (fig. 24a, d). 



The mandible has blunt teeth, the fourth and fifth very short and 

 obtuse (fig. 24/). 



The maxiUa has 12 spines and scarcely any notch below the upper 

 pair of large spines. The lower two spines are longer (fig. 24^^). 



The first cirrus has rami of 26 and 14 segments, those of the pos- 

 terior ramus strongly protuberant. The posterior ramus is about 

 two-thirds as long as the anterior. 



