THE SESSILE BARNACLES. 



237 



branch. There is an angle where the compartments join the basis. 

 Surface smooth, pinkish, or with the parietes faintly striped with 

 pink when cleaned. The radii are rather broad, very little sunken. 

 Tarietes not porous. The basis is boat-shaped or in form of a com- 

 pressed cone. It clasps the gorgonian from the lowest point of the 

 cone to its rostral end. It is permeated by small, rounded pores in 

 some examples, but solid except very close to the edge in others. The 

 barnacle is usually covered with the outer layer of the gorgonian, 

 but in most museum specimens this has been removed, leaving the 

 slender axis of the gorgonian and the barnacle nude, except for the 

 rather strong epidermis of the latter. 



Rostrocarinal length 20 mm., height 9^- mm. 



Rostrocarinal length 10 mm., height 8 mm. 



Rostrocarinal length 24 mm., height 8 mm. 



The scutum is somewhat concave externally, the apex obtuse or 

 truncate; sculpture of rather prominent growth-ridges. Articular 

 ridge prominent, terminating in a short, rounded point. No adduc- 

 tor ridge. 



The tergum has a peculiar square apex, due to the prominence of 

 the upper end of the articular rib. This is the distinctive mark of 

 B. galeatus. The spur is short, truncate, and about half the width 

 of the valve. Crests for the depressor muscles are scarcely indi- 

 cated. 



The first cirrus has rami of 12 and 7 segments, the anterior ramus 

 nearly twice as long as the posterior. Second cirrus with 9 and 8 

 segments, the anterior rarnus two segments longer. Neither of these 

 cirri have protuberant segments. Third cirrus similarly propor- 

 tioned, having 10 and 9 segments. The fourth to sixth cirri are alike. 

 The segments bear three pairs of spines and unusually long tufts at 

 the posterior sutures, the largest spines usually much longer than the 

 segments and nearly as long as the anterior pairs. I see no spinules 

 or " teeth " on any of the cirri, 



This is the only Conopea known to be American. It was a great 

 surprise to receive it from California, where a couple of dead speci- 

 mens were taken by the Albatross in deep w r ater. These are shown in 

 figure 75. 



It appears that B. galeatus is an old species, which has existed 

 since the Panamic connection between the two oceans. 



