e 
EXPLORATION OF ALASKA. 243 
a breadth of 2.0 and a height of about 3.0 mm.; the sheath of the 
radula projecting backward nearly 1.0 mm. ; the lip-disk sometimes 
surrounded by a ring of black pigment. The armature of the lip- 
disk entirely as shown (Pl. XI, figs. 1-4, 10-11) by me in the form 
from the Pacific, also the crop (Pl. XIII, fig. 2) of the bulbus.! 
The tongue in the eight specimens examined was provided with five, 
seven, eight, nine rows of plates, farther backwards also sixteen to 
twenty developed, and three younger rows ; the total number amount- 
ing thus to from twenty-seven to thirty.” The large lateral teeth? yellow 
in the body, especially in the anterior-inferior part, with commonly five 
to eight denticles on the inside of the hook ; sometimes, especially in 
the younger plates, the number of denticles rose to eleven to fifteen, 
sometimes the three to four outermost denticles were much larger than 
the rest, sometimes the denticulation was quite irregular; the height 
of this plate reached 0.4 mm. ‘The outer plates (Pl. XJ, fig. 1) com- 
monly four to six, seldom séven to eight; in a series of four on the 
hinder part of the tongue, the outermost measured about 0.05, the next 
0.09, 0.11, 0.125 mm.; they were quite colorless, compressed, with 
the upper side flattened, and rather erect. 
The salivary glands as in the purple-colored form from the Pacific. 
No constant dilatation of the middle of the @sophagus (as figured, 
Pl. I, f. 12g, by Alder and Hancock), but a strong, particular one at 
the root as figured (1. c. Pl. I, f. 12/) by Alder and Hancock and by 
me (Gatt. nordischer Doriden, |. c. Taf. XIX, fig. 14c). The 
stomach as in the Pacific form; the intestine sometimes dilated in its 
first part, sometimes absolutely of the same caliber as the rest, and 
neither externally vor internally different from it; a little bag 
(biliary sac) which has been noticed by Alder and Hancock (1. ¢. Pl. 
I, fig. 124), opening into the right side of this part of the intestine. 
The posterior visceral mass (liver) flattened and excavated on the 
anterior-inferior right half. The sanguineous gland whitish, convexo- 
concave, short and irregularly kidney-formed, with the excavation 
1 The first specimens of the Northern Atlantic left at my disposition 
being too small and too few for a thorough examination, I am obliged to 
refer to my examination given herewith of the form from the Pacific. Cf. 
moreover my figures in ‘‘Gatt. nord. Doriden,’’ 1. c. Pl. XIX, figs. 10, 11. 
The crop is rather well figured by Alder and Hane. (1. c. Pl. I, f, 12c). 
2 According to Meyer and Moebius, the number of plates (‘of the 
radula’’) is thirty-one, to Alder and Hancock, twenty-seven. 
3 Cf. my Gattungen nordischer Doriden, 1. c. Taf. XIX, fig. 12. 
