132 THE ANNELIDA POLYCHAETA. 



in length caudad to the end of the fragment, where the width, exclusive of the 

 parapodia, is, however, only .6 nun. and, inclusive of the parapodia, 1.4 mm ., and 

 to the tips of the setae near 3 nun. A second fragment, presumably from the 

 same specimen, farther caudad, is 9 mm. long, and consists of twenty somites. 

 A third fragment, which, judging from its coarseness is possibly from the middle 

 region of a second and larger specimen, is 17 mm. long, and consists of sixty-three 

 somites. 



The specimens at present are yellow and somewhat translucent, though in 

 Ufe probably transparent. The segmental organs are mostly dark in color, as 

 usual. 



The prostomium presents anteriorly in the middle a rounded protuberance 

 which is retracted or little obvious in some paratypes. From the dorsal surface 

 arises a slenderly conical median tentacle which is vertical, and typically curves 

 back close against the elevated portion of the prostomium between the eyes. 

 Farther forward and toward the sides are borne the paired tentacles, the ventral 

 of which are also conical. The eyes have their lenses directed strictly outwards, 

 the same axis being common to the two. (Plate 24, fig. 5). 



The proboscis in the type is about 3.8 mm. long, inclusive of its processes. 

 It is slender, widening gradually from base to distal end, and is smooth. At 

 the end it bears two long prehensorial processes, but otherwise lacks any papillae 

 or other processes about the opening. (Plate 24, fig. 4). 



The caudal edge of the mouth is straight. The tentacular cirri are nearly 

 equal in length. They are rather short, nearly cylindrical, but somewhat nar- 

 rowed and rounded at the distal ends. 



The somites are mostly smooth and entire, but a few of the most anterior 

 show a division into three or four rings, the parapodia being attached to the 

 most caudal of these. In the posterior portion of the anterior fragment of the 

 type the somites are twice as wide as long, while the third parapodia-bearing 

 somite is only once and a half as wide as long. The first parapodia are short, 

 but increase regularly in length and thickness in going caudad. The anterior 

 neurocirri appear to be much reduced in size, and are thin and ovate-acute in 

 form. Farther caudad the neuropodia become conspicuous and strongly setig- 

 erous. They are cylindrical, with a conical distal end, through the acutely pro- 

 longed tip of which protrudes the aciculum. The notocirri are foliaceous and 

 very broad, oval-orbicular, distally broadly rounded or even slightly notched 

 at middle. The neiuocirri of the typical somites are much smaller than the 

 corresponding notocirri. They are attached farther distad than the notocirri. 



