266 PROCEEDINGS OF THE ACADEMY OF [April, 



change to the last two or three segments of the anterior region, where 

 they rather abruptly become longer and thicker. On anterior seg- 

 ments of the second region they extend transversely across the dorsum 

 from the notopodia and meet medially, but though continuing to the 

 posterior end they become gradually smaller. Each includes a single 

 vascular loop, and is heavily ciliated along the medial margin. 



Notopodial capillary setae (PI. VIII, fig. 40) appear to be similar 

 throughout — soft, slender, tapered, regularly and closely provided with 

 obscure, incomplete sheaths, corresponding to slight internal camera- 

 tion. The fascicles are slightly more spreading anteriorly, more com- 

 pact and erect posteriorly. At the base of the notopodials on the 

 ventral side of the tuft are three or four small and delicate bifurcate 

 setae (fig. 42) with serrated stems and slender tapered prongs bearing 

 a series of long oblique hairs. Neuropodials of the posterior region 

 are mostly similar to the notopodials, but the sculptured region is 

 shorter, and in addition there is a ventral series of about six small 

 smooth blunt spines (fig. 41). Anterior neuropodials are arranged in 

 three nearly vertical series, the first extending most ventral. All are 

 stout, but those of the anterior two rows (fig. 39) bear slender terminal 

 portions similar in structure to the notopodial setae but much more 

 abruptly tapered; those of the posterior series are stout, curved, 

 smooth, clavate spines (fig. 38). Ventral to the palisade is a cres- 

 centic series of smaller capillary setae. All of these setae are stoutest 

 in the middle and posterior parapodia of the anterior region, but on 

 the last few transition segments rapidly become more slender and the 

 series short and restricted from the ventral end. Or it may be said 

 that the three series of stout spinous setae gradually disappear, finally 

 leaving only the ventral group of slender setae with a few small spines. 



Proboscis partially protruded on several specimens. It appears to 

 consist of four principal divisions, each again bilobate and bearing 

 from four to ten slender elongated processes with a continuous hem- 

 like raised border, leaving a longitudinal groove on each. The lobes 

 are often irregular and unequal and some specimens appear to have 

 the proboscis divided into from five to eight fimbriated lobes. 



Color in alcohol dull creamy yellow, more or less marked with brown 

 pigment which is most constant as three series of ventral spots, a 

 subneural and paired infra-podal. Others have the gills or parapodia 

 pigmented and others the dorsum marked with suffused spots or well- 

 defined annulations, while extreme forms may be deep chocolate 

 brown. 



This species appears to be quite plentiful between tides in the 



