360 STAUROCEPHALUS CILIATUS. 



dilation. Tentacles moniliform, scarcely half as long, much smaller in diameter than the 

 palpi, and springing from the dorsum of the head behind the eyes. Body about one inch 

 long, pale lavender, a yellow belt bounded by a red line on each side along the centre, 

 slightly tapered in front and more definitely diminished posteriorly, where it ends in two 

 caudal cirri. Proboscis has in the lower row a dense series of curved dark brown 

 denticles with a median and two lateral teeth, the maximum development occurring 

 toward the posterior third, and terminating in a thickened dark brown band with 

 irregular denticles. Upper row begins anteriorly in a series of pale brown horny fila- 

 ments which merge into the long teeth of the row. Posteriorly they diminish in 

 length, but increase in robustness, and terminate in a band of small denticles. An 

 accessory row externally on each side. Mandibles shaped like a boomerang, with a 

 series of eight deeply cut teeth on the anterior edge, besides three separate denticles 

 externally. Feet generally uniform, distinguished by a well-developed dorsal cirrus, 

 which commences on the second foot, containing a slender spine which goes as far as the 

 articulation of the considerable terminal process. Setigerous region large, bevelled 

 superiorly, and trending to the prominent inferior border. The obovate ventral cirrus 

 projects beyond it, less, however, than the dorsal cirrus. Two kinds of bristles 

 superiorly, viz., a long slender translucent form with an abrupt curve below the serra- 

 tions and a finely tapered tip, and a stronger bristle or two with a straight shaft and a 

 dilated, bifid extremity, one of the legs of the fork being shorter, broader, and more 

 acute at the tip. The inferior bristles compound, with curved shafts, and dilated, bevelled, 

 and serrated distal ends. Terminal piece with a bifid tip. 



Synonyms. 



1862. Prionognathus eiliatus, Keferstein. Zeitschr. f. wiss. Zool., Bd. xii, p. 99, Taf. viii,. f. 13 — 19. 



1885. Btauroce'phalus Chiajei, Cams. Fauna Medit., p. 217. 



1902. „ (third), Mcintosh. Ann. Nat. Hist., ser. 7, vol. x, p. 257. 



„ ,, (fourth), idem. Ibid., ser. 7, vol. x, p. 257. 



1904. „ ciliatus, Allen. Journ. M. B. A., n.s., vol. vii, p. 226. 



Habitat. — Under stones between tide-marks, St.- Peter Port, Guernsey, July, 1868 

 (W. 0. M.) ; Plymouth (Allen). 



Head flattened and tapered anteriorly to a blunt snout. Byes two, black, large 

 and distinct. Palpi arising from the sides of the snout in front of the eyes and having 

 a terminal articulation. Tentacles, scarcely half the length and much smaller in diameter 

 than the palpi, springing from the dorsum of the head behind the eyes, and moniliform 

 throughout. 



Body upwards of an inch long (25—30 mm., Keferstein), of a pale lavender hue, 

 marked along the centre of the dorsum by a yellow belt, bounded on each side by a red 

 line, probably from the blood-vessels. It is slightly tapered in front and more definitely 

 so posteriorly, where it ends in two caudal cirri. Segments numerous, the first and second 

 being devoid of feet. When preserved the feet of the anterior fifth are crowded, those 

 behind are less so. 



Proboscis.— In this and allied forms the food first comes under the action of the 

 serrated edges of the mandibles, and is then passed inward (upward) to the double 



