292 MR. CYRIL CROSSLAND ON THE [Feb. 16, 



i4bbon-like throughout the posterior two- thirds of its length. 

 Text-jfig. 43 represents sections of the body, drawn to scale and 

 illustrating these changes of shape. 



Text-fig. 43. 



Series of sections of the bodj' of IS. afra, drawn to scale to illustrate tlie changes 

 of shape in passing from the anterior to the posterior end. 



a. Section of buccal segment. 



6. „ of fourth setigerous segment. 



c. „ at beginning of gill-region, i. e. segment 22. 



d. „ at the middle of the body. 



e. „ about 2 inches before the anus. 



Prepared from a good-sized specimen from Chuaka. 



Gravier's figure of the prostomium and anterior end of the 

 body is apparently from an abnormally contracted specimen. The 

 two lobes of the former always diverge more, the peristomium is 

 longer and less swollen, and the tentacular cirri do not take so 

 rema,rkably lateral a position (compare figs. 1, 2, & 3, PI. XX.). 



According to Grube's tables *' this species belongs to that sub- 

 division of the genus characterised by the possession of tentacles 

 devoid of jointing ; but Gravier, while quoting this without 

 comment, figures indications of ringing. The fact is that though 

 in most specimens the tentacles appear smooth at first sight, more 

 or less ringing is sometimes quite obvious f and can always be made 

 out with care. The middle unpaired tentacle, which is from three 

 to four times the length of the prostomium, is considerably 

 longer than the other four, which are of about the same length. 

 Too great reliance on Grube's tables in this matter and in the size 

 of the gills leads to the separation of these specimens into two 

 or three species, as was done by Gravier, the validity of whose 

 species will be considered later. 



The jaws (text- fig. 44, p. 293) show no characteristic feature, and 



* Grube, Mitth. iiber die Familie der Euniceen. 



t In e. ff. two of the nine Chuaka specimens, and the Prison Island and Wasin 

 examples. It is clear too in one of those from the Sej'chelles, but not in the other. 



