FAMILY BALANIDA — BALANUS. 253 
BALANUS FISTULOSUS. 
PLATE XXXIV. FIG. 319. 
(STATE COLLECTION.) 
Balanus fistulosus. Bruce. Encyclop. Method, p. 166, pl. 164, figs. 7, 8. 
BS id. Lam. An. sans vert. Vol. 2, p. 496. Ed. Brux. 
B. elongatus. Gouxp, Invertebrata 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 coste towards 
their bases, dehiscent above. Aperture ample. 
Color. Soiled greenish above ; white or pinkish white on the tubular body. 
Height, 0°5 —1°0. 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. (Govutp, lc. p. 13.) Shell conical; the six triangles with irregular unequal 
longitudinal ribs marked across by distant incremental striz, and the smooth intervening spaces by 
deeply sculptured lines. T'wo anterior opercular valves deeply grooved or plaited; the two others 
rising above them likea beak. Color, purplish. Height, 1-5; diameter of base, 1*0. Acci- 
dental visiter. 
B. geniculaius. (Conran, Ac. Sc, -Vol. 6, p. 265, pl. 11, fig. 16. Govxp, l. c. fig. 9.) Prominent, 
flexuous, longitudinal, Ribs alternately larger and smaller, with two angular elevations on each, 
between which the valves are crossed by a carinate line. Opercular valves coarsely striated; 
aperture large. Color, greenish white. Height. 0-6; diameter of base, 1°0. Attached to P. 
magellanicus. Maine, Massachusetts. ’ 
B. rugosus, Montagu. (Goutp, |. c. p. 16.) Subeylindrical. Valves raised into angular points, 
coarsely and irregularly ribbed: aperture large, rhomboidal; opercle nearly smooth, with acute 
curved slightly diverging points. Color, white. Diameter of base, 0+75. Massachusetts. 
