SYLLILLE. 143 



notes that it would be interesting to see if T. Khronii has similar cseca. His fine figures 

 and good descriptions did much for this group. 



Eisig 1 considered the T-shaped glands or cseca of the alimentary canal of this group 

 and the casca of the Hesionida3 to be swim-bladders. 



Langerhans 2 follows Ehlers, Malmgren, and others, in grouping the Syllidge. He 

 makes three great divisions according to the condition of the palpi. Thus the Syllidse 

 proper have these separate ; the Exogonese have them fused, but prominent ; whilst the 

 AutolyteaB have them fused and grooved ventrally. These groups are subdivided by the 

 condition of the pharynx, the nature and number of the tentacles and tentacular cirri, 

 the condition of the head, and the first segment. He makes twenty-six genera of those 

 from Madeira, and points out that Syllides = Pionosyllis, and Pterosyllis = Amblyosyllis, 

 and that of forty-eight different genera by various authors only eleven stand. This 

 author did much to place the classification of the group on a more rational footing. 



Langerhans (1881) found a canal in the tooth of the proboscis in several genera, and 

 in Syttis aurantiaca, Grube, he met with a pair of glandular sacs on the dorsum of the 

 proboscis. He gives interesting notes on the budding of the Syllids. 



Haswell 3 (1885) found that Syllis corruscans had ova of a dull colour anteriorly, 

 whilst posteriorly an orange-coloured region bore sperms (with testicles, Malaquin). 

 The passage from the one to the other occurred abruptly at the 100th segment. At the 

 same epoch he observed a pair of large eyes on the first segment of the male region, and 

 the part was by-and-by detached as a pelagic male. 



De St. Joseph 4 found Labrostratus parasiticus and a Lumbriconereid parasitic in the 

 ccelom of various Syllids, viz. Eusyllis moniliconis, Syllis prolifera, Pionosyllis lamelligera, 

 and Grubea clavata. In this case the parasitism may be transitory, for others occur on 

 sea- weed (Bytiphloea). 



Malaquin, 5 in one of the most complete treatises on the structure, development, and 

 classification of the group, describes the Syllidae as a Family of Errant Annelids 

 (Polychseta), his diagnosis being: Cephalic segment provided with five appendages— viz. 

 two palpi, two lateral antennae and one median, and two pairs of eyes. The peristomial 

 (post-cephalic) segment has in general two pairs of tentacular cirri; sometimes only a 

 single pair. The succeeding segments have feet formed only of the setigerous lobe of the 

 ventral division, accompanied by a dorsal and a ventral cirrus. The dorsal division of 

 the foot appears at the epoch of sexual maturity. Pygidium with two cirri. Bristles 

 variable — simple or compound. The most general is the compound heterogomph with 

 bidentate tip. Proboscis protrusible — of two regions, the anterior (pharynx) chitinous, 

 cylindrical ; the second, the muscular proventriculus and ventriculus, being a secondary 

 development of the pharynx of the larva. Reproduction distinguished by the appearance 

 of secondary sexual characters ; the individual is transformed (epigamy), or gives rise to 

 a bud (schizogamy). 



1 < Mitth. Zool. Stat. Neap./ t. ii, p. 255. 



2 ' Zeitsch. f. w. Zool./ Bd. xxxii (1879). 



3 <Proc. Linn. Soc. N.S.W./ iv (1885), p. 733. 



4 ' Ann. Sc. Nat./ 7 e sei\, v, p. 221 (1888),and Gravier/Bull. Mus. Hist. Nat., Paris/ vi, p. 417 (1900). 



5 ' Kecherches sur les Syllidiens/ Lille, 1893, pp. 477, and 14 plates (4to). 



