602 A. M Verrill — Turhellaria, Nemertina, and 



out evident articulation or beading, while in true Syllis they are very 

 distinctly beaded or articulated. This was made the principal char- 

 acter of Eusyllis by Mcintosh. Langerhans restricted it to species 

 having the edge of the oesophagus denticulated, and in that sense it 

 is used by me. All the Bermuda Syllidae studied by me, except 

 OclontosylUs, Aiitolytus, and Gruheosyllis, have distinctly and 

 usually strongly articulated cirri. 



In most of the following species the blades are decidedly longer on 

 the upper than on the lower setie, and they are decidedly shorter on 

 the posterior segments than on the anterior, so that no very close 

 descriptions nor measurements can be briefl}^ given that would be 

 useful. Nor are the differences so marked as to be very useful for 

 the recognition of related species, even when figured, owing to the 

 variations of each. The forms of the palpi, antennoe, cirri, oesopha- 

 gus, and stomach afford better characters, though these are all able 

 to vary considerably by contraction. 



In our species of Syllis the oesophagus (or chitinous pharynx) has 

 a solitary, conical, median tooth, and usually a smooth anterior mar- 

 gin, becoming revolute when extruded from the mouth, but in a 

 few the margin is minutely crenulate, or it may be ill defined, pass- 

 ing gradually into the soft part. 



More than one species of Syllis was observed, in life, in the process 

 of producing one or more free sexual zooids by the alteration and 

 breaking away of a certain number of posterior segments, as in Auto- 

 lytus, and some were preserved with the fully formed zooids attached. 

 These agree with the genus Tetraglene. They have large eyes, with 

 a lens, but lack antennae and palpi. They have fascicles of long capil- 

 lary setae, in addition to the compound setae, and long beaded cirri. 

 Several specimens of Tetraglene were also taken in the surface tow- 

 ing-net, in the evening, about the last of May, associated with the 

 allied form of sexual zooids known as ChcetosylUs. 



But in related species of Syllis {S. corallicola, S. catennla, T. fer- 

 tilis) masses of ripe eggs were found along the posterior half of the 

 body, without any alteration of the segments, setae, or cirri. The 

 species of Syllis seem, therefore, to differ widely in their life his- 

 tories. 



Many of the following species of Syllidae were obtained by break- 

 ing up dead and decayed masses of corals, and placing them in 

 dishes of water for the annelids to crawl out. Others were obtained 

 by ))lacing masses of living corallines and sponges in the dishes, 

 especially at night, for the same purpose. 



