242 BIOLOGICAL SURVEY OF 



Order CIRRIPEDIA 



Suborder BALANAMORPHA 



Balanidae Acorn barnacles 



Balaninae 



Balanus Gronovius 



B. (Balanus) balanus (Linne). (Pilsbry, 1916, p. 149, pis. 

 33-35, text figs. 43^7.) Widely distributed on rock, shell, and 

 gravel bottoms, from low water to 300 feet. Stations: 30 

 dredging stations and S 4, 11, 12, 14, 24. 



B. (Balanus) crenatus Bruguiere. (Pilsbry, 1916, p. 165, 

 pis. 39, 40, text figs. 49-54.) Several specimens from Lithodes 

 maja (identified by Doctor Pilsbry) and from a Cancer. 



Doctor Pilsbry kindly informs us that the specimens sub- 

 mitted to him were the first of which he had any record as 

 occurring on crabs. The species is found on rocks and shells. 



B. (Semibalanus) balanoides (Linne). (Pilsbry, 1916, p. 

 182, pi. 44, text fig. 58.) Found everywhere on rocks, mol- 

 lusks, and piles, between tide marks. 



In the laboratory this species may be permanently sub- 

 merged in running sea water for weeks and still remain in 

 good health. The specimens grow rapidly under such condi- 

 tions. On small stones subjected to ice scour during the 

 winter this species is not found until July. 



Unidentified nauplius and cypris larvae of barnacles have 

 been taken in the plankton about the end of July. 



LITEEATUEE 



Darwin, Charles 1851 A monograph on the subclass Cirripedia, with figures 

 of all the species. The Lepadidae; or pedunculated cirripedes. Eay 

 Society, pp. i-xi, 1-400, 10 pL, 4 fig. 



1854 A monograph on the subclass Cirripedia, with figures of all 



the species. The Balanidae (or sessile cirripedes) ; the Verrucidae, 

 etc. Eay Society, pp. i-viii, 1-684, 30 pi., 11 fig. 



Pilsbry, H. A. 1907 The barnacles (Cirripedia) contained in the collections 

 of the U. S. National Museum. United States Nat. Mus., bull. 60, 

 pp. i-x, 1-122, 11 pi., 36 fig. 



1916 The sessile barnacles (Cirripedia) contained in the collections 



of the U. S. National Museum; including a monograph of the Ameri- 

 can species. United States Nat. Mus., bull. 93, pp. i-xi, 1-366, 76 pi., 

 99 fig. 



