354 STAUROCEPHALUS RITBROVITTATITS. 



1885. Staurocephalus rubrovittatus, Oarus. Fauna Medit., p. 217. 



1888. „ „ De St. Joseph. Ann. So. Nat., 7 e ser., t. v, p. 235, pi. x, f. 99. 



1895. m> 9J Pruvot and Eacovitza. Annel. Banyuls, in Arch. Zool. exper., 3 e 



ser., vol. iii, p. 349, pi. xv. 

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



}i y} „ Marenzeller. Polych. Grund., p. 15. 



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



1905. „ „ G-raeffe. Arbeit. Zool. Stat. Triest, xv, p. 322. 



1906. „ „ De St. Joseph. Ann. Sc Nat., 9 e ser., t. iii, p. 215. 



Habitat.- — The under surfaces of stones near low-water mark, and the larger stones 

 in pools at Herm (A. and R. M.), Devonshire (Col. Montagu), Plymouth (Allen). 



Extends to the Mediterranean and the continental side of the Channel. Grube first 

 procured it in the Adriatic, Pruvot found it common in tufts of Gystoseira at Roscoff. 

 Apparently the same form is mentioned by Malmgren from deep water in Fin mark. 



Head (Plate LV, fig. 1) somewhat rectangular, with four brownish-black eyes, the 

 anterior pair considerably larger (though hidden by the tentacles in the figure) than the 

 posterior, and wider apart. Two short clavate tentacles spring between the eyes of each 

 side, and extend nearly to the anterior edge of the snout. 1 Two curved or sickle- 

 shaped thick palpi arise below the snout and project on each side like horns. A slight 

 ciliated fillet is indicated on each side of the head posteriorly. 2 Head and appendages 

 pale, with palpocils on the anterior border (Pruvot and Racovitza). 



Body of fifty-three or fifty-four bristled segments, and fully an inch long (15 — 29 mm. 

 Pruvot and Racovitza), somewhat fusiform, slightly tapered from the anterior third 

 forward, and from rather more than the posterior third backward, and terminating in a 

 moderately tapered tail with two short cirri and a dorsal anus. The first segment has 

 no foot and is broader than the second. It is tinted of a fine rose-red, the " organs 

 nucaux " of Pruvot and Racovitza, which are developments of the anterior border of 

 the first segment, are innervated by the posterior lobe of the cephalic ganglia. 

 The second is paler, and also is devoid of feet. Bands of the same rose-red hue 

 cross the body from the anterior to the posterior end, being fainter in front and behind. 

 Each segment has two bands which cross the anterior and posterior parts (with a pale 

 belt between), diminishing to a point before reaching the bases of the feet. The tint of 

 each posterior band is somewhat deeper. The feet and cirri, with the ground-tint of the 

 body, are flesh or cream-coloured. 



The upper dental apparatus consists of two rows of dark brown horny teeth, the 

 inferior and inner (Plate LXI, fig. 7) being the stronger. This row commences anteriorly 

 in an irregularly differentiated horny band, which soon rises into distinct teeth separated 

 from each other, and of a complex nature. Twenty-one teeth on one side and twenty on 

 the other are visible in this part of the apparatus. These teeth (Plate LXI, fig. 7 a), like 



1 Ehlers represents four articulations in his examples, hut those procured in Herm, whether 

 imperfect or otherwise, were as described and as Pruvot and Racovitza state. In S. Chiaji, 

 Claparede, there are six segments. 



3 In the S. Chiaji of Claparede two ciliated pits, supposed to be sensory, occur at the posterior 

 border of the head; and two other vibratile pits are present inferiorly at the sides. 



