EXPLORATION OF ALASKA. 193 
filled by the glans, which had nearly the form of a human penis, with 
a well developed head with round aperture; this head seemed covered 
with very small, low and rounded, soft papilla. The spermatotheca 
were whitish, spherical, of the diameter of about 2.5 mm., filled with 
epithelium, fatty matter and altered semen; the chief duct a little 
longer than the spermatotheca, gradually passing into the simple 
vagina, that was about half as much in length (and was filled with 
sperma). The spermatocysta of violet-gray color, somewhat flattened, 
of oval outline, of the length of about 2.3 mm., filled with sperma. 
The posterior half, or a little less, of the large mucous and albuminous 
gland, chalk-white ; the anterior, more than half, of grayish or (on 
the left side) yellowish color; the structure as usual. 
A variety of the species (according to Dall, it also belongs to this 
species) was, moreover, obtained by Dr. Kennerly, in August, 1873, 
on alge, at low water, in Puget Sound, Washington Territory 
(fig. 6-9). 
The single individual was rather large; the length 40.0 mm., by a 
breadth of 28.0 mm., and a height of 13.0 mm.; the breadth of the 
foot 15.0 mm., of the margin of the mantle 11.0 mm.; the height of 
the rhinophoria 5.0 mm., of the branchial leaves nearly 5.0 mm. The 
color of the upper side obscure olive-gray, with rather large (diameter 
about 4.0 mm.) black and blackish spots; the under side yellowish. 
The general form and the head, with the tentacles, as above described. 
The openings of the rhinophor-holes as above, the club with about 
twenty five leaves. The branchial opening as above (diameter, 3.5 
mm.); the retracted branchial leaves six in number; the anal tube 
nearly 3.0 mm. high. The back villous, as in the typical individual. 
The foot as above. 
The peritoneum colorless, without larger spicula; but in the region 
of the ventricle of the heart the pericardium is brownish. 
.The central nervous system as above; the proximal olfactory 
ganglia bulbiform, a little larger than the buccal; the distal ones 
smaller than the proximal, at the root of the club of the rhinophoria. 
The buccal ganglia of oval form; the commissure between them 
being about one-third of the largest diameter of the ganglia. The eyes, 
the octocysts, the leaves of the rhinophoria and the villi of the back as 
above. 
The oral tube large, of a length and diameter of 40 mm. The 
bulbus pharyngeus 4.0 mm. long, by a height of 4 and a breadth of 
3.5 mm.; the sheath of the radula less prominent than in the former 
