110 MYSTIDES LIZZLE. 



species has comparatively short tentacles, but they may have been injured. Body linear, 

 elongate, segments numerous (forty-eight, Theel). Dorsal cirrus renif orm ; seti- 

 gerous lobe strong, bifid ; ventral cirrus ovate or ovato-rectangular. Distal end of shaft 

 of bristle has a hook-like spine with a smaller opposite it. 



Theel 1 founded this genus on the great length of the three pairs of tentacular cirri. 

 Eteone and Mysta have but two tentacular cirri ; Phyllodoce and Arteritis have four. His 

 example had no anal cirri, the body terminating in an obtuse cone. 



Levinsen (1883) gave Mystides two to three pairs of tentacles, small dorsal lamellge 

 (cirri), and three pairs of tentacular cirri. 



1. Mystides Lizzie, n.s. Plate L VIII, fig. 11 — head; Plate LXIX, figs. 11 and 12 — feet; 



Plate LXXVII, fig. 20— bristle. 



Specific Characters. — Head bluntly conical, with two large eyes widely separated and 

 situated towards the posterior border. Anterior tentacles slender and minute, situated 

 laterally. Three tentacular cirri — gradually increasing in length — at each side. They 

 are longer than the homologous organs in Eteone and appear to approach in length those 

 of Mysta, which, however, has only two. Body about three inches long; segments distinctly 

 marked by a deep furrow in front and by a lozenge-shaped depression after the anterior 

 third. Dorsal cirrus reniform, with a hilus at the base. The posterior differ from the 

 anterior chiefly in their tendency to form a point at the free dorsal edge, and in their 

 smaller size. The setigerous lobe is strong, bifid, and bevelled inferiorly. Distally the 

 dilated ends of the bristles have a curved, hook-like spine directed towards the serrated 

 edge of the terminal blade and with a spinous margin below it. A smaller spine occurs 

 on the opposite side. The terminal blade is broad at the base and gradually tapers to a 

 long and fine point. Its edge is minutely serrated. The ventral cirrus is ovate or ovato- 

 rectangular, barely reaching the tip of the setigerous process at the tenth foot, but more 

 nearly reaching it posteriorly, where the tip is less obtuse. Three madder-brown or 

 purplish bands on the dorsum, viz. a band at each side, and a median, which, however, 

 posteriorly is nearly severed into two by a pale median line. The pale portions between 

 the coloured belts also increase in distinctness posteriorly, so that the animal has a boldly- 

 marked series of bars. The dorsal cirri, with the exception of a few anteriorly, which 

 have a dark speck or two, are pale. 



Habitat. — Tossed on the West Sands, St. Andrews, after a storm in February, 1870, 

 when it was picked up by my sister. 



Off Cape Sagres, < Porcupine,' 1870. 



Head (Plate LVIII, fig. 11) bluntly conical, with two large eyes, widely separated 

 and situated towards the posterior border. The anterior tentacles are slender and minute 

 (whether from injury or otherwise is unknown), and they appear to be placed laterally 

 rather than at the tip of the snout. Three tentacular cirri occur on each side (on the 

 first, second, and third segments), and they increase in length from the first to the third. 

 They are longer than the homologous organs in Eteone, and appear to approach in length 



1 'Ann. Polych. Nouv.-Zemb./ p. 35, 1879. 



