AUTOLYTUS PROLIFER. 215 



and its contents. Langerhans describes it as diffused red, darkest at the tips of the 

 tentacles and cirri. From the tenth foot backward each has a small red speck (Langerhans). 

 Small specimens are pale, and Marenzeller states that twenty denticulations occur at the 

 opening of the proboscis into the gut. 



The feet (Plate LXXI, fig. 3) form short, blunt processes without a distinct ventral 

 lamella (cirrus). Dorsally is the pale tapered cirrus, which is comparatively short. The 

 massive setigerous region bears a group of strong, slightly curved bristles (Plate LXXIX, 

 figs. 22 and 22 a) resembling those of Autolytus pictus, the bevelled portion beyond the 

 dilated distal end of the shaft being spinous. The distal piece is short and bifid. On 

 immersion in spirit the pale cirri assumed a greenish hue. 



Further investigation may show that this form is a well-marked variety of Autolytus 

 pictus, but the opportunities for critical comparison have been so few that it has been 

 deemed best to leave the subject as it stands. 



Claparede points out the muscularity of the tentacles and tentacular cirri in this group 

 (e. g., Autolytus aurantiaca) and the presence of cilia on their surface. 



3. Autolytus pbolifer, 0. F. Midler, 1788. Plate XL VIII, fig. 6 (An. surculare; Plate 

 LX, fig. 4 — early larva, and figs. 5 and 5 a — anterior and posterior ends of free bud ; 

 Plate LXXI, fig. 4— foot of bud; Plate LXXIX, figs. 23 and 23 a— bristles. 

 Plate L, fig. 11 — pelagic male (Polybostrichus) . Plate XLIX, fig. 7 — pelagic 

 female (?), tinted like A. pictus, with ventral egg- sac. 



Specific Characters. — Head smoothly rounded in front ; eyes placed close together on 

 each side, but obliquely, so that the anterior are the wider apart. A long tapering median 

 cirrus and two lateral cirri. Two tentacular cirri on each side. All these processes are 

 smooth. Body about half an inch long, slightly and rather abruptly tapered anteriorly, more 

 distinctly tapered posteriorly, where it ends in two slender cirri. Colour pale yellowish, 

 somewhat darker in the middle from the intestine, and with numerous small whitish specks 

 over the latter. Ten papillae in pharynx (Langerhans). Foot with a comparatively short 

 dorsal cirrus with a distinctly marked cirrophore. The setigerous region is bluntly conical, 

 with short bristles abruptly dilated at the tip of the shaft, minutely spinose, and having a 

 short bifid terminal piece, the second of the two hooks being the larger. A single simple 

 bristle is generally present in each foot, the tip being bent and acutely pointed, as in 

 Autolytus fallax, Malmgren. 



Synonyms. 



Animal Surculare. 



1788. Nereis prolifera, 0. F. Miiller. Zool. Dame, II, p. 15, Tab. lii, f. 5—9. 

 1791. „ „ Gmelin. Linn. Syst. Nat., ed. 13, i, pt. 6, p. 3120. 



1806. „ „ Turton. Linn. Syst. Nat., iv, p. 90. 



1824. „ „ Bruguiere. Tabl. Bncycl. Meth., Vers, I, p. 134, Tab. lvi, f. 12—15. 



1825. „ „ De Blainville. Diet. Sc. Nat., xxxiv, p. 440. 

 1828. Nereisyllis prolifera, idem. Ibid., lvii, p. 473. 



1830. Nereis prolifera, Bosc. Vers, ed. 2, I, p. 174. 



