BARNACLES OF JAPAN AND BERING SEA. 75 
adductor and depressor muscle scars are moderately deep. It differs from the scutum of B. rostratus 
only in being somewhat more solid, with the adductor ridge a little better developed. 
The tergum is thin, rather fragile, narrow, its greatest width contained about 2 times in the 
length. Spur wide at the base, tapering to an obtuse, truncate end; situated close to the scutal 
margin; decidedly longer than that of B. rostratus. External sculpture of narrow oblique riblets, 
much stronger than in B. rostratus, the intervals faintly, weakly striate longitudinally. There is no 
groove from spur toward beak, only a flat, longitudinally and transversely striated band. The inte- 
rior is white throughout. Articular ridge rather narrow, arched, not much more than half the length 
of the valve, stronger than in B. rostratus. Articular furrow only weakly indicated. Crests for the 
depressor muscles rather weak and irregular, but much stronger than in B rostratus. 
Both of the opercular plates have a thin, yellowish cuticle, whitish in young specimens. 
The mandibles of no. 38667 have three rather stout short teeth, then a minute tooth and an 
obtuse lower angle. The upper tooth is minutely bifid at the tip. The upper and lower borders are 
densely and very finely hairy, as are also the intervals between the teeth (fig. 6 B). 
The maxilla; do not differ materially from those of B. rostratus as figured by Hoek, except that 
there are several small spines above the two great spines (fig. 6 C). 
The first cirrus (fig. 8 A) has very unequal rami of 15 and 27 segments, those of the posterior 
branch strongly protuberant at the anterior side, with dense hair-tufts. The second and third cirri 
also have unequal branches, the segments of both strongly protuberant, with dense tufts. Cirrus ii 
has 15 and 19 segments; cirrus iii, 12 and 19. Cirri iv to vi are of the usual slender and elongate 
shape, with subequal branches of about 35 segments. These segments are convex anteriorly, each 
with 6 or 7 pairs of spines, and having the usual posterior sutural groups of small spines. (Fig. 6 D, 
15th and 16th segments of cirrus v.) 
The penis is very long, over 20 mm., purplish, densely and conspicuously annulated, with a very 
few short hairs near the end. There is a blunt projection on the dorsal base. The cirri and mouth 
parts of the largest specimen in group no. 38670 agree fully with no. 38667. 
In this race the radii are scarcely sunken below the parietes. In the type lot the walls form a 
subcylindric shell, but in a group of seven individuals seated on a scallop shell, from station 4779, 
54 fathoms, the shell is more conic and smoother, the parietes yellowish or dirty white, the radii pure 
white. The largest specimen in this group measures 55 mm. high, 45 mm. in greatest diameter of 
the base. This group, no. 38670 U. S. National Museum, is figured in plate xn, figure 4. 
The cirri of the types of B. rostratus are not fully described. The first cirrus as described by 
Hoek agrees with B . rostratus apertus, except in having fewer segments, probably owing to its imma- 
ture condition or smaller size. The change in shape between the third and fourth cirri in B. rostratus 
apertus is quite abrupt. 
Balanus crenatus Bruguifere. [PI. xiv, fig. 1-9.] 
1853. B. crenatus Darwin, Monograph on the Cirripedia, Balanidse, p. 261. 
Localities: Union Bay, Bayne Sound, British Columbia shore, specimens no. 38671 and 38672 
U. S. National Museum; Albatross station no. 5008, Aniwa Bay, Saghalin Island, 24 fathoms, 
specimen no. 38674 U. S. National Museum; Albatross station no. 5038, near Urakawa Light, south 
coast of Hokkaido, 175 fathoms. 
Two forms of this species were taken on shore in Bayne Sound, British Columbia: No. 38671, 
a smooth, conic form with triangular parietes and delicately striate opercular plates, the specimen 
illustrated having a basal diameter of 14 mm. (pi. xiv, fig. 1, 2, 3); and no. 38672, in which the shell 
is more prism-shaped, or columnar with prominent angles, the old ones generally supporting a crop 
of younger barnacles at the summit. The opercular plates are much worn and are rather strongly 
striate. The figured group is 42 mm. high (pi. xiv, fig. 4-9). The examples from station 5008 are 
small and conic, but more rugged than no. 38671. 
