DOLABRIFERA. 127 



D. HOLLBOLLI Bergh. PI. 65, fig. 9 ; pi. 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-strije ; long-trape- 

 zoidal, with nearly parallel lateral borders, the apex strongly pro- 

 jecting, anterior end quite straight. Length 10 J, breadth 4i mill, 

 (fig. 9). 



Teeth differing from those of D. ascifera in having the cusps of 

 the laterals longer and slenderer (pi. 67, fig. 29, central tooth ; fig. 

 28, 1st lateral ; fig. 27, 30, two side teeth in profile). 



Greenland (Hollboll). 



D. hollbolli BERGH, Verb. k.-k. zool.-bot. Gesellsch. in Wien, 

 xxii, 1872, p. 438, pi. 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. 



