ART. 15 POLYCHAETOUS ANNELIDS FEOM OEIENT — TREADWELL 11 



A parapodium from near the middle of the body (fig. 15), has 

 a hemispherical notopodial lobe carrying on its outer margin a 

 conical projection into which the large acicula extends. In the 

 cirrus-bearing parapodia, the cirrus is attached to the extreme dor- 

 sal margin of the notopodial lobe, and extends to a short distance 

 beyond the longest setae. The cirrus tapers very gradually until 

 near the end, when it rapidly narrows. Throughout its length, 

 leaving only the slender terminal apex bare, the surface is studded 

 with villi, each equal in length to about one half the transverse di- 

 ameter of the cirrus. The neuropodium consists of a rounded post- 

 setal and conical pre-setal lobe, the acicula extending into the latter. 

 Beyond the apex of the acicula the lobe extends as a slender finger- 

 shaped process, very much narrower than the main portion of the 

 lobe. The post-setal lobe has the form of a blunt cone. The ven- 

 tral cirrus is conical and extends to the bases of the ventralmost 

 setae. Its surface is smooth. 



The notopodial setae arise in the form of a fan-shaped row from 

 the anterior face of the base of the notopodial lobe, the ventralmost 

 of the row overlapping the anterior face of the neuropodium. They 

 are all alike in form but differ in length. The shaft is stout, end- 

 ing in a single smooth, terminal, tooth. With the exception of the 

 terminal tooth, the whole seta carries series of regularly spaced 

 thin plates toothed at their margins and attached at an angle to 

 the shaft. These are most clearly seen when in profile, and then 

 (especially in the smaller setae), appear as if there were distinct 

 longitudinal rows, but at least in some cases, they extend entirely 

 around the shaft (fig. 16). The neuropodial setae are about equal 

 in length to the notopodial and have slightly more slender shafts. 

 Toward the end they widen rather abruptly, and then gradually 

 narrow to terminate in a curved apical tooth, with a second, sub- 

 apical, tooth arising near its base, the subapical tooth being much 

 smaller than the apical. The shaft of the seta and the terminal 

 toothed portion are smooth but the subterminal, w4der area carries 

 many toothed plates similar to those found on the notopodial setae. 

 I think that these do not extend entirely around the shaft but leave 

 entirely free a narrow strip on the side corresponding to the con- 

 vexity of the terminal tooth. (Fig. 17.) 



There are 15 pairs of elytra, carried on short stout elytrophores, 

 and they overlap so as to completely cover the dorsum of the animal. 

 The first pair had been lost. The second pair are kidney shaped 

 with a rather wide depression on the outer lateral margin. This 

 depression disappears in later elytra which are broad oval in out- 

 line. The second pair are pigmented for rather more than one 

 quarter of their surface. In preserved material this pigment is a 



