EXPLORATION OF ALASKA. TSi 
The specimen was of a uniform yellowish color; the rhinophoria 
finely dotted with brown (but not the branchial leaves). The length 
of the rather contracted and somewhat contorted individual was about 
18.0 mm. by a greatest breadth of 10.0 and a height of about 7.0 mm. 
the height of the (retracted) rhinophoria 2.5, of the tentacles ae 
1.5; of ai (retracted) gill 2.5 mm. ; the greatest breadth of the mantle- 
margin 3.5 mm., of the foot 5 0 mm. 
The form is sibonaes oval, the mantle-margin rather thick, not very 
broad. The back covered all over with very minute granules, some- 
times, especially on the middle of the back, crowded in irregular and 
roundish small groups; the under side of the mantle-margin smooth. 
The (contracted) openings of the rhinozhor-holes appear as a simple 
transverse slit, the granules of the back reaching forward to the open- 
ing, those in this neighborhood not larger than the rest. The club of 
the rhinophoria stout, with about thirty! broad leaves. The opening of 
the gill-cavity small, transverse, triangular-crescentic, with the convexity 
forwards (as contracted) ; the granules of the back reaching to the very 
margin of the gill-slit, but not larger than the rest. The gill consisting 
of eleven branchial leaves,” five lateral pairs and an anterior unpaired 
leaf; the anal tube low, truncate, nearly central; the renal pore at its 
right side. The head rather small; the tentacles digitiform, somewhat 
flattened. The sides of the body nearly imperceptible; the genital 
opening contracted.3 The foot rather strong, somewhat pointed at the 
end; the anterior margin with a deep furrow, the superior lip rather 
strong and prominent, cleft in the median line. 
The peritoneum with very fine dark points (brown-black) spread 
everywhere ; entirely without true spicules. 
The central, nervous system showed the cerebro-visceral ganglia 
somewhat elongate, thicker and broader in the pesterior part, nearly 
not excavated in the exterior margin; the pedal ones of oval form, 
larger than the visceral. The olfactory ganglia very short-stalked, 
bulbiform, a little smaller than the buccal; a small optic ganglion, the 
optic nerve short. At the inferior side of the posterior part of the 
right visceral (fig 1a) ganglion is a short-stalked (fig. 15) ganglion 
genitale giving off several nerves, one of them has at its root another 
ganglion (fig. lc). The common commissure not longer than the 
1 Alder and Hancock mention merely ten to fifteen leaves. 
» Alder and Hancock mention fifteen leaves. 
3 The representation of the penis (?) (1. ¢. Pl. 5, f. 3) by Alder and Han- 
cock cannot be correct. 
