458 PROCEEDINGS OF THE ACADEMY OF [Juiie, 



head is an elongated, narrow, triangular, depressed, translucent area 

 reaching from the apex to the mouth, into which the annular grooves 

 do not extend, thus cutting off on each side lateral portions of the 

 rings, wliich appear as four pairs of low, thick, slightly projecting lobes 

 to which the depressed form of the head is chiefly due. The 4 apical 

 tentacles are present in but one example, and even in this are imperfect 

 through maceration. Palpi (lateral lips), a pair of prominent rounded 

 lobes, with largely free, thin, anterior margins at the sides of the mouth. 

 Peristomium indistinctly separated from the base of the prostomium 

 and the first foot-bearing somite; ventrally it forms a prominent 

 median lip. In two of the small examples from Sta. 3,771 and one 

 larger from Sta. 3,695, a minute cirrus is present just in line with the 

 parapodia on the buccal ring, but cannot be detected in the type speci- 

 men, which is the largest examined. It is possible that the buccal ring 

 may consist of two somites in this genus. 



Except the first, all foot-bearing somites are distinct, and in the 

 anterior region about 3 to 3^ times as -wide as long, increasing in size to 

 about XLV, then remaining without material change to LXIII, be- 

 tween which and LXII a weakening of the body walls occurs, caudad 

 of which the width rapidly decreases for 4 or 5 somites, beyond which 

 the body assumes a linear form, though the much increased length of 

 the parapodia results in a greater total width and a more depressed 

 aspect than anteriorly. About 100 somites constitute the posterior 

 region; the type has 97, but 3 or 4 caudal somites are wanting. Some 

 smaller specimens -^ith the anal ring present lack caudal cirri, which 

 have doubtless been lost. 



As typical of the anterior region the parapodium of somite XV may 

 be described. This consists of a rather stout neuropodium having a 

 length equal to h the mdth of the somite, and divided into a broad, 

 foliaceous, ovate pyriform presetal lobe, the tip of which is divided by 

 a deep cleft into two narrow tongue-like halves, and a somewhat slen- 

 der lanceolate postsetal lobe, placed just opposite to the cleft in the 

 presetal lobe, which it slightly exceeds in length, ^'entral cirrus arises 

 from basal half of neuropodium, rather thick and stout; its tip falls a 

 httle short of the setigerous lobes. Dorsal cirrus consists of a rather 

 stout rounded stalk, with swollen base and somewhat flattened, foli- 

 aceous, nearly orbicular or broadly ovate-lanceolate appendage, which 

 bends abruptly dorsad. 



Toward the head the postsetal lobe becomes shorter than the pre- 

 setal, and is absent in the first 3 parapodia; the presetal also becomes 

 narrower, and finally loses the terminal bifurcation; the cirri approach 



