ARICIIDAE. 353 



posterior ones are only slight, broadly rounded lips separated by a shallow emar- 

 gination. Neurocirri attached on ventral surface well distad of middle of para- 

 podium, stout at base, but strongly tapered distad like the presetal lobe, which 

 is a little smaller. The notocirrus is attached on the side of the segment a little 

 above the base of the parapodium. It is a pale, short, subcyclindrical, distally 

 rounded papilla. No branchiae or branchiform organs are present. On the 

 fifth parapodia the dorsal presetal lobe is scarcely evident, though normally 

 developed on the sixth, while on the anterior four pairs it is quite absent, leaving 

 a single, pointed, presetal lobe. The first two pairs of parapodia much reduced, 

 as usual; both retain the neurocirrus. 



Acicula two in each parapodium, with the notopodial the stouter; tapered 

 to rather fine, curving tips; pale. The composite neuropodial setae are char- 

 acterized by their pecuhar sockets; the sides of the socket are long and flare 

 widely apart, the tips curving ectad away from the base of the terminal piece. 



The eight anterior segments present in the type have a length of 50 mm. 

 Greatest width, exclusive of parapodia, 4 mm. 



Locality. Peru: 111 miles N. W. of Aguja Point. Sta. 4651 (lat. 5° 42' 

 S., long. 83° W.). Depth 2,222 fms. Bottom of fine sticky gray mud. Bottom 

 temp. 34.5° F. 11 November, 1904. 



This species appears to come from the greatest depth recorded for a glyc- 

 erid. 



Ariciidae. 



These are typically elongate polychaetes, in which the body is commonly 

 obviously flattened dorsally and convex ventrally; pointed at both ends, but 

 more strongly so caudad. Somites short. Body very fragile. Commonly of 

 a rose- tint. 



The prostomium is in the form of a cone devoid of processes. Eyes may be 

 either present or absent. 



Peristomium without processes, achaetous. 



Parapodia normally subdorsal in position; often dorsolateral anteriorly 

 and dorsal in position posteriorly. Biramous. Rows of tubercles on caudal 

 surface of the anterior pairs often present (Aricia). Often dividing the body 

 into two regions by differences in their form and in the character of the setae 

 borne. 



Setae simple, normally of several types, always including an elongate, distally 

 acute form which is strongly cross-ridged, appearing to be annulated or camer- 



