NO. 5 HARTMAN : POLYCHAETOUS ANNELIDS 493 



somewhat folded, extending back through the first 5 setigerous segments. 

 Its walls are thin and membranous. 



The second, or first setigerous, segment resembles those farther back 

 except that its dorsal cirri are somewhat larger (pi. 59, fig. 2). It is 

 provided with dorsal and ventral cirri and a setigerous lobe between the 

 cirri. From the fourth setigerous segment the dorsal cirrophore comes to 

 have a thick base and is already somewhat pigmented but by the sixth 

 segment the dark pigment extends completely around the stalk. The 

 typical appearance (pi. 59, fig. 8) is continued farther back through all 

 parapodia to the end of the body. 



Notopodia are represented only by the large cirri and single embedded 

 acicula. Notoacicula, like all other setal structures, are clear yellow or 

 translucent. Neuropodial lobes are well developed, provided with a 

 strong single aciculum and a fascicle of 12 to 14 long, slender setae. The 

 setae are of a single kind but of varying lengths. The superiormost tend 

 to be longest and they decrease in length inferiorly. All are falcate (pi. 

 59, fig. 4) with bifurcated tip but in the slenderer, longer ones this struc- 

 ture can be discerned only under high magnification. Each seta consists 

 of a long, nearly cylindrical (pi. 59, fig. 7) shaft, a knifelike blade with a 

 single row of oblique teeth which in cross section is long triangular (pi. 

 59, fig. 6) ; the tip is strongly bifid. In lateral view the accessory tooth is 

 seen to be somewhat overhung by the larger main tooth and in frontal 

 view (pi. 59, fig. 5) the main tooth appears unusually broad. One sel- 

 dom sees a broken tip indicating comparative great strength of the struc- 

 ture. 



The body terminates posteriorly in a ringlike pygidium with a 

 terminal anal aperture. It is papillated dorsally but smooth ventrally. 

 This ring is provided laterally with a pair of fusiform processes which 

 are also papillated (pi. 59, fig. 3) ; they resemble the dorsal cirri of 

 parapodia. 



Color in life is drab greenish yellow with bright reddish brown cirro- 

 phores. The species is known to inhabit sandy mud flats, especially in 

 eel grass zones, at low water line and in shallow depths to 16 fms. 



In the original account of this species the delineations of the pros- 

 tomial lobes, palpi and peristomium were not clarified. In the illustra- 

 tion of the head the palpostyles and prostomial antennae appear to be 

 attached to the base of the palpi. Actually the antennae are not a part 

 of the palpi. Furthermore the notoaciculum is shown extending only 

 partly through the notopodium; in the material examined it extends 



