468 



PROCEEDINGS OF THE NATIONAL MUSEUM. 



There are two pair of eyes, not noticeably different in size, the 

 anterior being a little farther apart than the posterior and with 

 much more prominent lenses. 



The jaws are rather large, broad-flattened plates much curved 

 toward the ends. Each has a row of denticulations along the inner 

 edge. They are light brown at the base, but much darker toward 



the apex. The paragnaths 

 are small, dark brown in 

 color: I, two small ones 

 lying one behind the other; 

 II, a cluster of about 7; III 

 and IV, apparently run to- 

 gether, the two being repre- 

 sented on either side by a 

 patch of about 15; V, two 

 oval paragnaths larger than 

 the others ; VI, three, almost 

 continuous with the basal 

 armature, which extends en- 

 tirely around the pharynx. 



The parapodia are of prac- 

 tically uniform character 

 throughout the body. The 

 tenth (fig. 2) shows all lobes 

 of practically the same 

 length, none very long or 

 sharp pointed. The dorsal 

 cirrus is conical, the ventral 

 one much more slender, at- 

 tached rather closely to the 

 neuropodium. 



Two kinds of compound 

 setae occur in the notopo- 

 dium and only one in the 

 neuropodium. One (fig. 3) 

 has a stout basal portion 

 with many transverse stria- 

 tions; the terminal joint 

 small, blunt pointed, with a row of stout spines along one edge. 

 These spines vary in number and size, but this variation is, I think, 

 due to the loss or injury of some of them. The second form of seta 

 (fig. 4) has a slender basal joint, the terminal joint being very long 

 and slender. There is a faint indication of striations along one 

 margin. Both forms occur in the notopodium, but only the latter in 

 the neuropodium. 



Type.— Csit. No. 18934, U. S. N. M. 



Figs. 1-4.— Nereis brevicirrata, new species, l, Head 

 X 7.5; 2, Tenth parapodium y 22.5; 3, Compound 

 seta X 250; 4, Compound seta X 300 



