108 MYSTA BAKBATA. 



superior lamella, projects beyond the setigerous region. The inferior lamella becomes 

 more pointed externally from the thirtieth foot backward, and at the hundredth the tip 

 has also a tendency to a point ventrally. 



A curious two-jointed parasite occurs on the dorsal lamella of the fiftieth foot. 



This species presents certain resemblances to the Eteone cxca of Ehlers, 1 from the 

 6 Porcupine ' Expedition of 1869, but the latter has no eyes, and the tentacular cirri seem 

 to be longer. The presence or absence of eyes, however, in spirit-preparation is an 

 uncertain character. 



Eteone flava, Fabr., a form not uncommon in more northern waters, has not yet been 

 found in British seas. What relationship the Eteone fucata of M. Sars 2 has to this or 

 allied forms it is difficult to say. In all probability it is identical with one or other of the 

 forms mentioned by Malmgren. 



Genus XXXVII.— Mysta, Malmgren, 1865. 



Head bluntly conical. Eyes two, conspicuous, situated at the posterior border. 

 Tentacles short and subulate, as in Eteone. Tentacular cirri, two on each side, unequal, 

 subulate, fixed to the first segment. Body linear, slightly flattened, tapered towards 

 each extremity. Two anal cirri. Proboscis long, sub-cylindrical, thickened anteriorly, 

 papillaB ovate-fusiform in linear rows. Foot with the dorsal cirrus sub-orbicular, seti- 

 gerous lobe bifid ; ventral cirrus ovato-lanceolate. Bristles have the ends of the shafts 

 dilated with a large curved spine, and a smaller at the tip with minute spines on the 

 ridges. The terminal blade is wide beneath, tapers to a fine point, and has a serrated edge. 



This genus resembles Eteone, and by some is made a sub-genus. 



1. Mysta barbata, Malmgren, 1865. Plate LVIIL fig. 10— head ; PL LXIX, fig. 10- 

 foot; PL LXXVII, fig. 19— bristle. 



Specific Characters. — Head (in spirit) bluntly conical, with two conspicuous eyes 

 posteriorly. At the truncated apex are two short subulate tentacles on each side. 

 Tentacular cirri two on each side, a dorsal and a ventral, the former more than twice the 

 length of the latter, thick at the base, but tapering to a fine point. Body slightly 

 diminished towards the head, and more distinctly so posteriorly. A brownish band passes 

 from the head backward within the line of the lamellse on each side, and a median stripe 

 of similar hue runs along the ridge of the dorsum. Dorsal cirri sub-orbicular, having a 

 longer transverse diameter in the anterior feet, and a longer obliquely vertical diameter 

 in the posterior feet. The setigerous lobe is somewhat small and bifid. The bristles 

 show a large curved spine and a smaller one opposite it, and the ridges of the dilated 

 ends of the shafts are spinous. The terminal blade is wide beneath, tapers to a nne 

 point, and the edge is serrated. The ventral cirrus is ovato-lanceolate. 



1 ' Zeitsoh. f. w. Zool./ Bd. xxv, 1875, p. 42, Taf. ii, figs. 12—14. 

 3 ' Vidensk.-Selsk. Forliandl./ 1871, (sep. copy) p. 4. 



