DOLABRIFERA. 127 
D. HOLLBOLLI Bergh. PI. 65, fig. 9; pl. 62, figs. 5, 6, 7, 8. 
Dimensions of contracted specimen, length 25, breadth 22, alt. 16 
mill. Body short and stout ; back elevated, smooth above, the sides 
irregularly knotted by contraction. Gill slit weakly curved, gaping 
behind. Mantle of moderate breadth. Anus situated as usual, at 
the posterior end of mantle. Gill (fig. 5) dark gray-brownish, the 
right side most developed, each side having 5-6 larger branches, 
Foot extending somewhat behind body, and projecting in front in 
rounded lobes each side of the head (fig. 8). Sole rather large and 
wide. Color dark olive-brownish, darkest at the lateral margins and 
here and there on the sole; the sides of the upper surface having here 
and there scattered, dark, more red-brown irregular spots, about 2 
mill. in diameter; and in a few places the same color occurs more 
diffused and also on the edges of the upper tentacles. The lens 
shows fine (gland-) openings all over the back. Anterior tentacles 
are like the rhinophores, but edges more reflexed, especially below 
where they overlap somewhat, Rhinophores short-pedicelled auri- 
culate, somewhat funnel-shaped above, deeply cleft down the outer 
sides. Between the tentacles and rhinophores, but more separated, 
are the very distinct black eyes. 
Shell extremely thin, membranous, weakly bent longitudinally 
and laterally, pale yellowish, with fine growth-strie; long-trape- 
zoidal, with nearly parallel lateral borders, the apex strongly pro- 
jecting, anterior end quite straight. Length 103, breadth 44 mill. 
(fig. 9). 
Teeth differing from those of D. ascifera in having the cusps of 
the laterals longer and slenderer (pl. 67, fig. 29, central tooth; fig. 
28, Ist lateral; fig. 27, 30, two side teeth in profile). 
Greenland (Hollbéll). 
D. holiboli Berau, Verh. k.-k. zool.-bot. Gesellsch. in Wien, 
xxii, 1872, p. 438, pl. 5, f. 1-24. 
It is remarkable that a species of this tropical group should occur 
in Greenland seas. The longer shell with less excised sinus, and 
the longer and slenderer cusps of the lateral teeth are points of 
difference between this species and D. ascifera. But one specimen 
is known. PI. 62, fig. 7, front view; fig. 6, side view; fig. 8, head 
from below. 
