47 154 Proceedings of the Royal Irish Academy. 



DESCRIPTION OF PLATES. 

 Plate I. 



F: ? . 



1. Etogone hebes var. liibernieo. var. no v. 

 1 a. Anterior end, dorsal view, x 60. 



1 b. Head, x 170. 



1 c . Anal segment, x 120. 



1 D. Foot from anterior region, x 330. 



1 E. Foot from posterior region, showing arrangement of setae. x400. 



1 F. Setae, x 850. a = simple setae : h = compound setae ; c = tip of a spine. 



1 G. Tooth in the pharynx. 



1 H. Ciliated sacs entering posterior part of the proventriculus. 



2. SphaerosyUis hvlbosa sp. n. 



2 a. Anterior end, dorsal view, x 85. 

 2 B. Posterior end, dorsal view, x 85. 



2 c. Xuchal organ and tentacular cirrus, light side, x 530. 

 2 d. Fifth foot, x 350. 



Plate II. 



2. SphaerosyUis bullosa sp. n. (continued). 



2 E. Setae from the second setigerous segment, x 850. a = compound 

 setae ; b - simple dorsal setae ; c = spine. 



2 f. Setae from the twenty-fourth setigerous segment, x 850. a = com- 

 pound setae ; b = dorsal simple seta ; c = spine. 



2 G. Simple dorsal seta from a posterior foot, x 850. 



3. StreptosyUis Websteri sp. n. 



3 a. Anterior end, dorsal view, x 66. 

 3 b. Posterior end, dorsal view, x 66. 

 3 c. Third foot, x 330. 



3 D. Sixteenth foot, x 330. 



3 E. Setae from third foot, x 850. a = dorsal simple seta : l = compound 

 seta with long tip ; e = compound seta with short tip ; d = spine. 



3 F. Setae from sixteenth foot, x 850. a = dorsal simple seta ; b = com- 



pound seta ; c = spine ; o = distal end of the shaft of a compound 

 seta ; e = terminal piece of a compound seta. 



Plate TIL 

 ■i. Streptosyllls bidentata sp. n. 

 •1 a Anterior end, dorsal view, x 66. 



4 b. Head, ventral view. x 66. 



