Gatty Marine Lahoratory ^ St. Andrews. 147 



along the convex side, and slightly enlarged and bifid at tiie 

 end.'-" Beneath this is a fan-like tuft of compound bristles 

 with slightly curved shafts and somewhat long terminal pieces 

 which are bifid at the end and with a serrated edge. 

 Further, sexually mature examples have after segment viii. 

 a tuft of delicate capillary bristles which spring from the 

 posterior base of the setigerous process. 



JNIr. Moore refers the foregoing form to the Syllidse, and 

 thinks that it may be the species referred to by Verrill as 

 having been taken at Woods Holl along with S. setosa *, and 

 is perhaps the S. lonyicirrata, CEvsttd, of Webster and Bene- 

 dict, but is not that species as described by European authors. 

 From typical species of the genus he points out that it ditfers 

 in the small size and ventral position of the palpi. 



Mr. Moore's careful description demonstrates the grounds 

 on which the resemblances to the Syllids are based, yet there 

 is another group with which it might be compared, viz. the 

 Staurocephalidse. The head (prostomium) is somewhat like 

 that of Aiitotylus or Myrianida, with a median and two 

 lateral tentacles, the eyes being arranged like those of the 

 Syllids and Staurocepha/us, the anterior rudimentary pair 

 being, however, peculiar. The absence of a median tentacle 

 in Stauroceplialus is a divergence, but in some Stauro- 

 cephalids the tentacles are more or less ringed. The body 

 offers little that is diagnostic in general outline, but the 

 caudal region has a pygidium with a short median style, as 

 well as two long lateral cirri, features diverging from the 

 Staurocephalids, which usually have only the lateral cirri. 

 The structure of the foot is, perhaps, the most critical feature 

 in the comparison. In Mr. Moore's form the foot is strictly 

 uuiramous on the first seven bristled segments in sexually 

 mature forms and in all the segments in the immatuie 

 anneluls. In all ordinary Syllids the foot conforms to the 

 uuiramous type, having only a single spine and bristles of 

 one character, the ventral cirrus often being fused with the 

 lower border of the setigerous process, which usually has a 

 different outline from that in Syllides verrilli. In the 

 Staurocephalidi3e the foot, on the other hand, though there 

 is but one spine, shows a biraraous tendency in so far as the 

 bristles are in two tufts, and tlie upper dorsal bristles diverge 

 in structure from the others, and, in all, the ventral cirrus is 

 carried far out on the setigerous process. 



To go more minutely into the structure of the foot of 

 Syllides verrilli, the dorsal cirrus is proportionally massive 



* Rep. U.S. Fisli. Comra. for 18S2 (1834), p. 664, footnote. 



