ON A REMARKABLE SYLLIS-BUD. 15 



increases in size, occupying accordingly a good deal of the 

 body cavity 1 ). 



Segmental organs coloured by a dark pigment seem to 

 have been observed also by Grube in Odontosyllis hyalina 2 ), 

 a worm which probably also must be considered as a bud ; 

 here he found in the posterior region of the body , situa- 

 ted on each side of the nerve-cord, black coiled tubes, 

 opening on the ventral side. However by the shape of its 

 bristles, and its smooth dorsal cirri, this species is quite 

 different from our specimens. 



J) Mittheil. aus der Zool. Station zu Neapel , Bd. VII, p. 20. 



2) Beitr'age zur Anneliden-fauna der Philippinen, p. 129. Taf. VII, fig. 1. 



EXPLANATION OP THE PLATES. 



PLATE 1. 



Fig. 1. Foot of the S//!lis-bud. X 90 diam. 

 u 2. a. Ventral bristle; b. tips of three dorsal epitocous bristles. Enlarged. 

 „ 3. Anal region of one specimen. X 36 diam. 

 h 4. Ventral view of three feet , showing the different state of extrusion 



of the segmental organs. X 36 diam. 

 a 5. Segmental organ of the second segment with its funnel. Highly enlarged. 

 k 6. Lateral half of a transverse section of the body, showing the position 

 of the segmental organ; 



c. nerve-cord; i. intestine; n. segmental organ. 

 n 7. Transverse section of a segmental organ. X 90 diam. 

 » 8. Diagrammatical view of a segmental organ: a in state of rest; 



b. in state of extrusion; e. epidermis; m. muscle. 

 » 9. Transverse section (not quite vertical) through the head, showing one 

 dorsal and one ventral eye; 

 p. pigment-layer of retina; r. rod-layer of the same; re. layer of 

 retinal cells; v. vitreous body. X 90 diam. 



PLATE 2. 



Fig. 1. Ventral view of the head and anterior region of a Syllis-hai, showing 

 the extruded segmental organs. X 10 diam. 



Notes from the Leytlen Museum, Vol. XI. 



