200 SYLLIS CORNUTA. 



the differences in section of the ordinary and thefswimming-bristles, and the structure of 

 the pigment-spots and glands in the sexual bud. 



In 1893 De St. Joseph observed that he had found specimens of thirty-eight and 

 forty-six segments, with orange segmental organs, and filled with rose-coloured sperms, 

 and acephalous buds of twenty-eight and seventeen segments loaded with sperms and 

 having swimming-bristles. A spot of violet pigment occurred at the base of some of the 

 dorsal cirri. He did not consider the Syllis hamata of Claparede identical with Syllis 

 spongicola, Grube. 



The structure of the proventriculus of this species is described by Malaquin 1 as 

 similar to that of Syllis hyalina, Grube, which is^mtermediate between the Autolyti and 

 the Eusyllides. The intimate structure of the muscular columns is, however, more complex, 

 for four or five transverse striations are present. 



The same author 2 describes and figures the ovaries of this species — in the lateral 

 regions of the body — as having a large cgecal blood-vessel in their midst. Each is sur- 

 rounded by a follicular membrane. 



In Gravier's 8. djiboutiensis, which resembles this form in general aspect, the dorsal 

 cirrus is shorter, and the ventral still more so, whilst the bifid tip to the distal end of the 

 bristle is noteworthy. 



8. Syllis cornuta, H. Rathke, 1843. Plate LXX, figs. 22-22 b— feet ; Plate LXXIX, 



figs. 16-16 b — bristles. 



Specific Characters. — Head transversely ovoid, with four eyes in a semicircle. Palpi 

 elongate ovoid, soldered at the base. Median and lateral tentacles and the tentacular cirri 

 long and moniliform. Dorsal cirri in the middle of the body have 17 — 20 or more articu- 

 lations. Body moderately elongated. Foot with a dorsal cirrus gently tapering from a 

 point a little above the base to the tip. Setigerous region conical, bearing one or more very 

 large spines, and a series of falciform bristles, the bevelled ends of the shafts being 

 smooth. The upper bristles have very long narrow terminal processes, which are slightly 

 bent, like a curved bistoury, in lateral view, and minutely bifid at the extremity. The 

 lower bristles have shorter hooked tips spinous along the edge, the last spine being the 

 secondary process beneath the hook. The ventral cirrus is sausage-shaped with a tapering 

 tip extending as far outward as the setigerous region. 



Synonyms. 

 1843. Syllis cornuta, H. Rathke. Beitrage z. Fauna Xorw., p. 164, Taf. vii, f. 12. 

 1851. „ „ Grube. Fain. Annel., pp. 61 and 132. 



1865. „ „ Johnston. Cat. Brit. Mus., pp. 192 and 342, 



„ „ „ De Quatrefages. Annel., II, p. 23. 



1867. „ „ Malmgren. Annul. Polych., p. 43, Taf. viii, f. 45. 



1869. „ „ Mcintosh. Trans. E. S. Edin., xxv, p. 415, pi. xvi, f. 15. 



1874. „ „ Malm. Op. cit. Goteb., p. 82. 



1 'Mitt. Zool. Stat. Neap./ pp. 228 and 229. 

 3 Op. cit., 1893, p. 377. 



