130 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL.22 



median segments the innermost one is replaced by a thick, falcate spine 

 (Plate 14, fig. 1) accompanied by a long, slender seta like those in 

 anterior segments. In far posterior segments, the setal ridges are gradually 

 shoved dorsolaterally from a strict lateral position. A pair surround the 

 broad, dorsally directed terminal anal pore. The parapodia of the last 

 3 segments are similar to others except that the spines are thicker ( Plate 

 14, fig. 2), forming an anal armature. 



Brada glabra differs from other species of the genus in totally lacking 

 epithelial papillae, except for the interramal one. Parapodia are reduced 

 to setal ridges from which the spinelike setae project. It is known only 

 from southern California, in moderate to basin depths, and in sediments 

 of silt. 



Genus ILYPHAGUS Chamberlin, 1919 



Ilyphagus ilyvestis, new species 

 (Plate 13, figs. 1-3) 



Two specimens were taken in Long Basin (Sta. 6351). They grossly 

 resemble a gray, flat, compacted and elongated mudcake. They measure 

 to 14 mm long by 6.2 mm wide. The general shape is reminiscent of a 

 very flat Brada, densely clothed above and below with very long, slender 

 papillae; these are thickly coated with mud for half their length and 

 exposed at the distal ends. The body is truncate in front and broadly 

 rounded behind (Plate 13, fig. 1 ) ; it lacks a cephalic cage. The prostomial 

 parts are fully retracted and could not be distinguished by dissection. 

 The parapodial parts, largely obscured by the densely mud-coated papil- 

 lae, seem to be inconspicuous low mounds from which the setal fascicles 

 project in biramous arrangement. The number of segments has not been 

 accurately determined but may not exceed 40. 



Parapodial fascicles are lateral, visible as glistening white or straw- 

 colored, very fine, slender, distally pointed hairs; there are no falcigers or 

 hooks of any kind. Seen under high magnification, they are closely cross- 

 barred for all or most of their length, with the bars wider than long and 

 similar throughout the area of barring. Neuropodial setae are coarser 

 and fewer than notopodial ones; in the posterior half of the body they 

 number about 5 in a fascicle. Each is a simple rod, expanded subdistally 

 to a bladelike part and tapering to a slender filament (Plate 13, fig. 2). 

 Notopodial setae are about twice as numerous, extend farther distally, 

 and are slenderer, similarly cross-barred and taper distally to long slender 

 ends (Plate 13, fig. 3). 



