EXPLORATION OF ALASKA. 223 
skin between the warts, as well as the warts themselves, showed the 
white spicules everywhere shining through ; the spicules often project- 
ing from the surface of the warts The spicules for the greater part 
very large, long, and reaching a diameter of at least 0.05 mm.; they 
were strongly calcified, mostly straight or slightly curved, the surface 
nearly even. In the interstitial tissue were rather many spicules; but 
(as in the rhinophoria) less calcified than in the skin. 
The mouth-tube rather wide. The, bulbus pharyngeus of nearly 
usual form, about 1.6 mm. long; the sheath of the radula, moreover, 
projecting backwards about 0.4 mm., bent somewhat upwards or down- 
wards; the lip-disk with a rather thick yellowish cuticula ; the sucking- 
crop large, larger than the true bulbus, to which it adheres by a very 
short petiolus. The tongue with nine rows of teeth, further back 
twenty to thirty-two developed and three younger rows; the total 
number of rows, thirty-two to forty-four.!. The yellow median plates 
(fig. 10a) about 0.05 mm. long, of the usual form. The large lateral 
plates yellow, of about 0.12 mm. height; the form as usual; the hook 
with about fifteen to sixteen fine denticles, and a strong tooth at the 
inside of the base (fig. 1056). The external plate colorless, about 0.04 
mm. in height, with the usual rudiment of a hook (fig. 10¢, 110).? 
The salivary glands white, rather thick, making two or three short 
coils at the sides of the esophagus. The: cesophagus as usual. The 
intestine emerging from the liver at about the middle of its length ; 
the biliary sac (fig. 18) is at the pyloric part of it, situated deeply, 
scarcely showing itself on the surface of the liver and opening (fig. 
18a) into the stomach close to the pylorus. The liver about 6.5 mm. 
long by a breadth of 3.0 mm. and a height of 2.0 mm., deeply excav- 
ated in the anterior third of its right side, and of light yellow color. 
The sanguineous gland much flattened, whitish, heart-formed, of about 
1.5 mm. largest diameter. The renal chamber rather wide, the tube 
on its floor strong. 
' Meyer and Moebius (1. c. p. 73) mention twenty-nine rows ; Alder and 
Hancock thirty. 
2 The representations of the external plate by Meyer and Moebius (1. c. 
fig. 2, 6) are not natural. Alder and Hance. (1. c., Part VII, p. ii, Pl. 46, 
supplem. text) mention two external plates in their D. muricata (as in their 
D. diaphana) ; either the D. muricata of A. and H. must be another species, 
or they must have fallen into error from the particular view which is some- 
times had in certain positions of the hind ends of the large lateral teeth 
with the external ones. 
