CORYNOCEPHALUS PAUMOTANUS. 141 



CoRTNOCEPHALus Levinsen. 



Kongl. Danske vidensk. sselsk. Skrifter naturvid. math., 1885-86, 3, p. 327; Apstein, Ergebn. Atlant. 

 Ocean * * * Plankton-exped., 1900, 2, H. b., p 14. 



Of this genus one species, which is new, was secured, making the fourth 

 known. It may be placed by means of the following key: 



Key to Species. 



a. Somites distinctly bipartite on ventral side C. albomacuUilits Levinsen. 



aa. Somites ventrally entire. 



6. Axes of eyes meeting at a right angle C. tenuis Apstein. 



66. Axes of eyes forming a straight transverse line. 



c. Median tentacle blunt, attached far in front of axes of ej'es C. ■pawnotanus, sp. nov. 



cc. Median tentacle slender, attached at or caudad of level of axes of eyes . . . . C. gazellae Apstein. 



CORTNOCEPHALTJS PAUMOTANUS, Sp. noV. 



Plate 23, fig. 1-3. 



The body at present is a dilute yellowish, excepting the segmental glands, 

 which are dark purphsh brown; the eyes are also darker than the general body 

 and of a somewhat orange cast. 



The body consists of fifty somites ia addition to the prostomium. The 

 total length is 28 mm. The greatest width, exclusive of the parapodia, is 2 mm., 

 and, inclusive of the parapodia, 3.7 mm. The body is flattened dorsoventrally. 

 It is widest in the middle region, from which it narrows to a point at the caudal 

 end, and also narrows strongly cephalad, the first somites being abruptly much 

 narrower than the prostomium, inclusive of the eyes. 



The prostomimn is elevated between the eyes hke a short half cylinder 

 placed transversely. A low, subconical projection on its anterior face represents 

 the median tentacle. In front of this elevated region is a depressed, sub quadrate 

 lobe projecting in front of the eyes; the anterior corners are rounded and the 

 anterior margin is mesally a httle mcurved. This lobe projects broadly ventrad 

 of the general level and its plain ventral surface bears the four paired ten- 

 tacles. The paired tentacles are large, flattened, lanceolate, foUaceous struc- 

 tures, of which the posterior pair are the larger. On the anterior edge at the 

 base of each is a small dark spot. The eyes are large and project prominently 

 laterad, their axes lying in a common straight, transverse Une. (Plate 23, fig. 1, 2). 



Except at the extreme ends of the body, the somites are of nearly uniform 



