AUTOLYTTTS PICTITS. 211 



In the seventh case a nurse-stock of twenty-eight segments bears a chain of stolons 

 from one to seven in number. Malaquin is of opinion that where the chain of buds is 

 smaller than the nurse-stock it is a case of budding, whereas when the stolon is larger or 

 as large as the nurse-stock it is a case of fission. 



Langerhans makes this his third tribe, and divides it into seven sub-sections, viz., 

 flurysyllis, Ehlers; Anoplosyllis, Claparede; Heterosyllis, Claparede; Autolytus, Grrube ; 

 Procerxa, Ehlers ; Myrianida, Aud. and Edwards ; and Virchoivia, Langerhans. 



The British forms fall under only three of these, viz., Autolytus, Procersea, and 

 Myrianida; and if, as appears to be right, the first two ought to be conjoined, then only 

 two genera are represented in our fauna. 



Langerhans distinguishes Procersea from Autolytus by the presence of elongated cirri 

 on the first, second, and third segments of the body, the latter {Autolytus) only having 

 these on the first and second. Moreover, he points out that the pharynx has twenty teeth 

 (papillae) — ten larger and ten smaller. 



De St. Joseph included Procersea and Stephanosyllis under Autolytus, and his 

 description of the genus corresponded for the most part with that now given. He also 

 noted that one group, Autoly tides, Malaquin, has an unarmed proboscis. 1 



As Calvin Mensch 2 points out, only one bud is borne at a time in this genus and in 

 Autolytus cornutus of Agassiz, who demonstrated the relationship of- (Ersted's Polybostrichus 

 (1843) and J. Muller's Sacconereis (1853). 



1. Autolytus pictus, Ehlers, 1864. Plate XL VII, fig. 1— male bud; Plate XLIX, fig. 8— 

 nurse-stock; Plate LXXI, fig. 2— foot; Plate LXXIX, fig. 21— bristle. 



Specific Characters. — Head somewhat small, rounded in front, long diameter antero- 

 posterior. Eyes four, the anterior pair the wider apart, in some connate, and both have 

 lenses. Two lateral and a longer and thicker median tentacle, all of a madder-brown hue. 

 The tentacular cirri are less elongated but of the same colour. Body about one inch long, 

 and of about 100 segments ; slightly narrowed anteriorly and more distinctly so posteriorly, 

 where it terminates in two short, flattened, and curved cirri about twice the length of the 

 last segment. Dorsum marked by a pale central band with numerous and regular transverse 

 spurs, which cut the brown (sepia) pigment into oblong spaces. Beneath and external to 

 the latter is a pale lateral belt into which the transverse spurs run. Just above the feet 

 a dark brown belt passes from end to end, intersected here and there, opposite the pale 

 transverse spurs, by narrow pale lines. First twelve or thirteen segments are darker and 

 have the ground colour paler than the rest. Ventral surface pale or flesh-coloured. 

 Foot carries a short dorsal cirrus (except anteriorly) which shows slight crenations when 

 coiled. Setigerous process short and truncated, with comparatively short bristles, the 

 shaft of which is stout, enlarged distally, bevelled at the edges, and spinous. Terminal 

 piece short and broad, with a bifid tip, the lower hook being the larger. 



i < Ann. Sc. Nat./ 7 e ser., I, 1887. 



2 " On the Life-History of Autolytus cornutus and Alternation of Generations in Annelids/' 

 < Americ. Nat./ vol. xxxiv, p. 165 (1900). 



