122 THE ANNELIDA POLYCHAETA. 



clavato-elliptic outline, with the teeth few, minute, and widely separated. 

 Locality. Between Mexico and Paumotu Islands: Sta. 4742 (lat. 0° 04' S., 

 long. 117° 07' W.). 300 fms. to surface. Surface temp. 77° F. Exped. 1904- 

 1905. One specimen. 



Pelagobia Greeff. 



Zeitschr. wiss. zool., 1879, 32, p. 247, pi. 14, fig. 23-25; Reibisch, Ergebn. Atlant. Ocean * * * Plankton- 

 exped., 1895, 2, H. c, p. 21; Bergstrom, Zool. bidrag., 1914, 3, p. 112, 185, 186. 



Key to Species. 



a. Shaft of setae wholly smooth P. viguieri Gravier. 



aa. Shaft of setae more or less serrate. 



h. No eyes; teeth of shaft of setae easily seen under moderate magnification. .P. serrata Southern. 

 bb. Eyes; teeth of shaft of setae visible only under strong magnification. . . .P. longicirrata Greeff. 



Pelagobia viguieri Gravier. 



Deux, exped. Antarc. Franc. 1908-1910. Annel., 1911, p. 62; Bergstrom, Zool. bidrag., 1914, 3, p. 188. 

 ?Pelagobia longicirrata Ehlers, Nat. Antarc. exped. Nat. hist., 1912, p. 14. 

 Pelagobia viguieri Bergstrom, Zool. bidrag., 1914, 3, p. 188. 



The general color is yellow, with the prostomium and first few somites often 

 more or less distinctly orange. The cirri appear paler, more whitish. The 

 setae are colorless and transparent. 



A specimen 12 mm. in length has a maximum width, exclusive of the para- 

 podia, of 1.5 mm., and to the end of the setae, of about 4 mm. The number 

 of somites is normally near thirty-three. Back of the head the body is con- 

 stricted over several somites, then widens gradually but decidedly to the middle 

 region, behind which it narrows again gradually to the pointed caudal extremity. 



The prostomium proper is short and broad, but clearly narrower than 

 the succeeding somite. It is broadly rounded anteriorly, bulging more convexly 

 between the tentacles. The tentacles of each side are widely separated from 

 those of the opposite side. They are short and very slender, acuminate, and 

 translucent. 



The first somite is clearly discrete from the prostomium and from the second 

 somite. It is thickened, projecting out on all sides beyond the prostomium and 

 usually the second somite as well. It is of nearly the same length as the pros- 

 tomium, or mesally above scarcely shorter. The tentacular cirri subequal, rather 

 long, reaching caudad to the sixth somite, or sometimes not so far. The style 



