'312 ANNELIDA FROM BERMUDA. 



Fam. NEREIDS. 



NEEEIS Cuvier. 

 Nereis Bairdii, n. sp. 



(Plate VIII, Figs. 22-28.) 



The head of this species (Fig. 22) is quite long, the anterior thirds 

 set off from each other and bounded by lines curving inward ; the pos- 

 terior third with convex sides ; posterior margin straight. 



Eyes not very large, circular, lateral. 



Antennae about one-half as long as the head, removed from each 

 other, at origin, by less than their own diameter ; inserted in slight 

 depressions of the anterior margin of the head ; bluntly conical. 



Palpi very long, not large, not tai)ering, with large terminal articles, 

 which, in alcoholic specimens, are nearly spherical. 



The buccal segment, in contracted specimens, has the same length 

 as the second segment ; probably double that length in life. 



The maxillary ring of the proboscis is short (Figs. 22-'', 23) ; the parag- 

 nathi are complete; mostly conical; arrangement, i, irregularly Y- 

 shaped; ii, double series, irregular ; iii, two transverse, linear series; iv, 

 numerous, irregular; v, sometimes wanting, sometimes one, two, or 

 three, small ; vi, on each side a single, narrow, elongated transverse 

 denticle, ends rounded ; situated on elevations (Fig. 22) which have 

 straight inner margins ; outer margins straight to near the anterior end, 

 when they curve inward ; vii and viii in two series, the anterior com- 

 posed of a few large denticles, the posterior more numerous and smaller. 



Tentacular cirri with stout cylindrical basal articles ; the cirri them- 

 selves delicate; the posterior superior longest, reaching back to the 

 eighth segment ; the others much shorter, as shown in the figure. 



Feet rather stout and short ; on the anterior segments (Fig. 24) the 

 linguliie and rami are nearly of the same length, stout, conical. Dorsal 

 cirrus arising from the ui)per margin of its lingula, stout, conical, not 

 reaching quite to the end of the lingula. Ventral ramus bi-labiate; an- 

 terior lip a little longer than the posterior. Ventral cirrus arising just 

 within the base of its lingula, delicate, Ihiger-shaped, nearly as long as 

 the lingula. Further back the feet undergo some changes. The su- 

 perior lingula is enlarged (Fig. 25), the dorsal cirrus moves nearer the 

 apex of its lingula, and on the extreme posterior feet becomes a little 

 more delicate (Fig. 20.) The dorsalramus becomes smaller, more shari)ly 

 conical. The ventral ramus shortens, esi)ecially its anterior lip. The 



