224 PROCEEDINGS OF THE ACADEMY OF [April, 



larger than the others and nearly connate, but no swimming setae 

 exist on any of the small number of anterior segments present. 



Of the tentacular cirri (fig. 9) the dorsal peristomial is about four 

 times as long as the prostomium, that of somite II is slightly longer 

 and of III as much shorter ; the ventral peristomial cirrus is about two 

 and one-half times the prostomial length. All of the tentacular cirri 

 resemble the cephalic cirri in being slender, delicate, and not monili- 

 form, or with indistinct irregular furrows only. 



After the second, the segments increase very gradually in length 

 and more rapidly in width and soon assume the depressed form char- 

 acterizing the middle region where they are five or six times as wide as 

 long. The type specimen has about 150 somites, the cotype only 

 110. Posteriorly the body becomes slender and ends in a minute 

 annular pygidium, bearing on its ventral side a pair of very slender 

 caudal cirri equalling the last twelve segments and exceeding any of 

 the cephalic appendages. 



> The parapodia are of the form usual in Syllidse and project promi- 

 nently from the sides at a low level. Although there is no distinct 

 notopodium, a slender notopodial aciculus is always present just be- 

 neath the notopodial cirrophore (fig. 10). The well-developed neu- 

 ropodium terminates in a broadly rounded, more dorsal, postsetal 

 process and a longer, rather prominent, and more ventral presetal 

 process. The three or four aciculi terminate at the upper outer angle 

 of the former. Ventral cirri are always short, stout and bluntly 

 rounded, with oblique bases passing into the ventral surface of the 

 body, and in size about equal the neuropodia. Notopodial cirri arise 

 from very large and prominent cirrophores. Except for their slightly 

 larger size anteriorly, where they are about three times the length of 

 the prostomium, the notopodial styles are similar throughout. They 

 are probably somewhat contracted and in life would be longer and more 

 slender. In the middle of the body they are scarcely one-half of the 

 total width. As shown in the figm-e they are rather stout and coarse, 

 and, though more or less deeply marked wdth irregular transverse fur- 

 rows, are never regularly articulated or moniliform. The only varia- 

 tion in the parapodia is that they become more prominent in all their 

 parts posteriorly. 



Notopodial aciculi are slender, curved and acutely pointed; the 

 neuropodial are stouter, nearly straight and knobbed at the end. All 

 setae (fig. 11) are compound and all are subacicular in position. In 

 middle parapodia they are numerous, arranged in about ten horizontal 

 rows of three to five each, or about forty in all. They are colorless. 



