402 THE ANNELIDA POLYCHAETA. 



Ilyphagus, gen. nov.^ 



Body broad in comparison with length, rounded at both ends, at neither of 

 which it is otherwise much attenuated. 



Characters of prostomium unknown. 



Parapodia bu-amous, without obvious setigerous prominences. 



Setae all simple, strongly cross-striate, or annulated, as usual. Those of 

 the notopodial fascicles capillary, very fine, uniform. Those of the neuropodia 

 very much coarser, straight, or nearly so, long, narrowing to a fine tip, not in 

 crochet-form. The setae of the most anterior somites not specially elongate 

 and not forming a "cage." 



The surface of the body densely clothed with hair-like filaments, more or 

 less uniformly arranged, and completely cloaking the body. Integument non- 

 tuberculate. 



Genotype. — /. bythincola, sp. nov. 



Differing from Brada in lacking a tuberculated integument and in being 

 densely and uniformly clothed with long, fine filaments. The neuropodial setae 

 are relatively much larger and are not suggestive of the crochet-type. 



Ilyphagus bythincola, sp. nov.^ 

 Plate 69, fig. 4-9. 



The three type-specimens are deformed by pressure. All are densely 

 clothed with closely adherent mud. The anterior end is retracted, preventing 

 satisfactory exainination of the prostomium and its appendages. 



The largest specimen is 50 mm. long, and in its present flattened condition 

 measures 25 nam., or half the length, across the middle. The number of somites, 

 while not precisely determinable, is small, not exceeding forty. 



The entire body is covered with a dense, felt-like coat of slender, hair-hke, 

 uniform, cuticular filaments. The ventral setae are conspicuously coarser 

 than the dorsals. They are yellow, or somewhat straw-colored. In the middle 

 region eight, or about that number, in each fascicle. Each seta narrows con- 

 tinuously and conspicuously distad, being drawn out into a long, fine, straight, 

 or somewhat curved, tip. The seta also narrows toward the base. The annuli 



' 'iXiis, mud, and ^ayos, a glutton. 



- Pvdos, deeps of the sea, and incola, inhabitant. 



