192 SYLLIDiB. 



great development and form, to conjecture that the frontal lobes of 

 this worm are analogous to the exterior antennae of the Nereides ; and 

 it may be considered as giving support to the opinion of Blainville, 

 who had come to this conclusion from the examination of species in 

 which their development is much less remarkable, and where there 

 was little coincidence in their figure * . 



Ohs, Of a pale yellowish-brown colour. The body tapers at the 

 tail. The foot is obtuse, and furnished with a single fascicle of com- 

 pound colourless bristles, the terminal piece short and falcate. 



Plate XV. A. Fig. I. /SyZZis armiZ/am, natural size. 2. The same mag- 

 nified. 2 %. The head more highly magnified. 



2. S. cornuta, head longer than broad, with two much produced 

 lobes in front ; antennae not produced beyond the lobes, moniliform ; 

 eyes in a semicircle behind, the anterior pair widest apart ; dorsal 

 cirri moniliform, not longer than the diameter of the body ; ventral 

 cirrus small and papillary. Length 1". 



Syllis cornuta, if. Rathke in Act. Nov. Curios. Ccesar. (1843) xx. 164. 

 tab. 7. f. 12. 



Hab. Oyster beds. 



Obs. A specimen ^ths of an inch in length had about 100 seg- 

 ments, and was of a pale straw-colour. Eyes minute. Antennae and 

 tentacular cirri nearly equal in length and of the same form. Dorsal 

 cirrus upwards and downwards alternately. Tail with two moniliform 

 styles. Bristles stout comparatively with a small falcate piece, ciliated 

 on the inner edge, articulated to the incrassated and obliquely cut 

 end of the shaft. After death the appendages become much more 

 distinctly moniliform. — F. D. Dyster, 



3. S. prolifera, head rounded and entire in front, without lobes ; 

 antennae elongated, filiform, unjointed ; eyes in a square ; dorsal 

 cirri about twice as long as the diameter of the body, very ob- 

 scurely jointed ; inferior cirrus small, conical. Length 6-8'". 

 Plate XV. A. figs. 3, 4. 



Nereis prolifera. Mull. Zool. Dan. ii. 15. tab. 52. f. 5-9, copied in En- 

 cyclop. Method. Vers, pi. 56. f. 12-15, and in Jones's Anim. Kingd. 

 221. f. 95. Turt. Gmel. iv. 90. Bosc, Vers, i. 174. Aud. 8f M.- 

 Edw. in Ann. des Sc. nat. xxix. 231, and Hist. Litt. de la France, 

 ii. 209. 



Nereisyllis prolifera, Blainv. Diet. Ivii. 473. 



Syllis prolifera, Johnst. in Ann. &f Mag. Nat. Hist. xv. 146. pi. 9. f. 3, 4. 



Autolytus prolifera, Grube, Fam. Annel. 62. 



Hab. The coralline region. 



Desc. Body rather more than half an inch in length, scolopendri- 

 * Diet, des Sc. Nat. IviL 474. 



