NO. 1 HARTMAN : POLYCHAETOUS ANNELIDS 75 



terior pair near the base of the ceratophore (pi. 20, fig. 245). The 

 median antenna is conspicuous, its ceratophore curved downward, the 

 style long, slender (pi. 20, fig. 244). 



The everted proboscis (745-37) terminates in 11 dorsal and 11 

 ventral, soft papillae. Jaws are amber colored, with 2 large dorsal and 

 2 ventral fangs, but without lateral accessory teeth. 



The elytra are visible only after removing the sandy covering. They 

 have long, club-shaped processes along their inner and posterior margins 

 (pi. 20, fig. 252), which project slightly above the sand particles. The 

 surface extends laterally to conceal the parapodia and most of the setae 

 (thus contrasting with the condition in P. spinosa). The long, lateral 

 fringe extends laterally nearly as far as the neuropodial setae. The 

 dorsal surface is overlain with papillae to which foreign particles ad- 

 here. The elytrophoral scar is elongate, near the inner side, and there 

 is no incision (pi. 20, fig. 252). 



Parapodia are much as in P. spinosa, the notopodium is short, 

 papillar, with numerous fine, hair-like, serrated notopodial setae (pi. 20, 

 fig. 248). These fascicles are notably smaller and less conspicuous (pi. 

 20, fig. 251) than in P. spinosa. The neuropodia are proportionately 

 shorter, and less papillated except on the ventral surface where the 

 papillae are long, filiform. Neuropodia include stouter, superior (pi. 20, 

 fig. 254) and median setae (pi. 20, fig. 253), and finer, slenderer in- 

 ferior setae (pi. 20, fig. 247). The superior setae have a somewhat 

 spinose shaft and an appendage that is slightly falcate, its length less 

 than three times its greatest width (pi. 20, fig. 254). The median setae 

 are similar to the superior, but the shaft is almost smooth and the ap- 

 pendage is about as broad as long or only slightly longer (pi. 20, fig. 

 253). The inferior setae have a long, slender appendage with entire (pi. 

 20, fig. 247) or bifid tip. The first few parapodia (posterior to the first) 

 have composite neuropodial setae in which the shaft is strongly serrated, 

 the appendage long, slender, with entire tip (pi. 20, figs. 246, 250), or 

 bifid tip (pi. 20, fig. 249). 



P. fitnbriata differs from P. spinosa in that the parapodia are pro- 

 portionately shorter, the shafts of the superior neuropodial setae are 

 almost smooth, the prostomial structures differ (see figures above). 



Holotype. — AHF no, 15. 



Distribution. — Isabel Island, Sinaloa, Mexico (Holotype) ; Thurloe 

 Bay, Gulf of California; Secas Islands, Panama. In 8 to 25 fms. 



