family balanidje balanus. 253 



Balanus fistulosus. 



PLATE XXXIV. FIG. 319. 



(STATE COLLECTION.) 



Balanus fistulosus. Brug. Encyclop. Method, p. 166, pi. 164, figs. 7, 8. 

 B. id. Lam. An. sans vert. Vol. 2, p. 496. Ed. Brus. 



B. elongatus. Gould, Inrerte'irata of Mass. p. 18, fig. 8. 



Description. Shells gregarious, crowded, elongated, tubular, with irregular rings often 

 strangulated, larger at the summit than at the base, vertically striated for more than half the 

 length, vertically rugose towards the summit. Valves with concentric elevated costae towards 

 their bases, dehiscent above. Aperture ample. 



Colo?-. Soiled greenish above ; white or pinkish white on the tubular body. 



Height, 0'5 - I'O. Diameter of aperture, 0'2 ; of base, 0'15. 



This is a common species on our coast, attached generally to docks, wharves, and other 

 submerged timber exposed to the flow and recess of the tides. They are so strongly grega- 

 rious, that it is not uncommon to see a single specimen with clusters of others attached to the 

 circumference of its aperture. They are often much shorter and broader than the dimensions 

 given above. Some conchologists are inclined to believe it to be a variety of B. miser or 

 ovularis, but with this opinion I cannot coincide. Its constant and regular occurrence in 

 places where it had ample room for development, forbids the supposition of its being an 

 accidental variety. 



{EXTRA-LIMITAL.) 



B. tintinnabulum, Lin. (Gould, 1. c. p. 13.) Shell conical; the six triangles with irregular unequal 

 lonoritudinal ribs marked across by distant incremental stride, and the smooth intervening spaces by 

 deeply sculptured lines. Two anterior opercular valves deeply grooved or plaited ; the two others 

 rising above them like a beak. Color, purplish. Height, 1*5; diameter of base, 1*0. Acci- 

 dental visiter. 



B. geniculatus. (Conrad, Ac. Sc. Vol. 6, p. 265, pi. 11, fig. IG. Gould, 1. c. fig. 9.) Prominent, 

 flexuous, longitudinal Ribs ahernately larger and smaller, with two angular elevations on each, 

 between which the valves arc crossed by a carinate line. Opercular valves coarsely striated; 

 aperture large. Color, greenish white. Height. 0-6; diameter of base, I'O. Attached to P. 

 magellanicus. Maine, Massachusetts. 



B. rugosus, Montagu. (Gould, 1. c. p. IG.) Subcyhndrical. Valves raised into angular points, 

 coarsely and irregularly ribbed : aperture large, rhomboidal ; opcrcle nearly smooth, with acute 

 curved slightly diverging points. Color, white. Diameter of base, 0'75. Massachusetts. 



