56 THE ANNELIDA POLYCHAETA. 



The parapodia are short, being considerably shorter than the width of 

 the somite to which they are attached, excepting in the narrower caudal region. 

 They appear flattened in the cephalocaudal direction. Depth proximally 

 great and equalling or exceeding the length exclusive of the setae. Narrowing 

 moderately distad, the dorsal edge being nearly horizontal and the ventral 

 oblique. The two rami are distinct and well separated, the neuropodium a httle 

 exceeding the notopodium. Each branch is conically narrowed and drawn out 

 distally into a slender acicular process. The neurocirri are very small, short 

 and subulate. Each is attached at the middle of the ventral surface and reaches 

 to the distal end of the neuropodium proper or a little beyond it, but not to the 

 end of the acicular process excepting in the second parapodia. The neurocirri 

 of the second somite are much longer, extending beyond the ends of the setae. 

 The notocirri are slender and filiform, distally subulate. They extend out well 

 beyond the tips of the setae. Their cirrophores are attached close to the bases 

 of the notopodia and are large and conical. (Plate 1, fig. 2). 



In each branch of the parapodium there is a single aciculum which is pale 

 yellow in color and is plainly transversely striate. The tip of the neuropodial 

 aciculum projects freely at the side of the tip of the acicular process, which 

 exceeds the aciculum. The notopodial aciculum extends through the acicular 

 process and exceeds the neuropodial. The notopodial setae are in a spreading 

 whorl, diverging distad and bending mesad conspicuously over the dorsum, 

 especially in the caudal region, much as in yokahamiensis. They are pale yellow 

 in color. Each is typically a blade-like structure widest at its middle, narrowing 

 moderately proximad and distally narrowing to an acute point. One side is 

 more nearly straight than the other and is commonly a little concave or angu- 

 larly inbent, the other edge being convex. One of the broad surfaces is com- 

 monly concave and the other convex, or the seta in cross-section at the widest 

 part may be subtriangular. On the convex side there are numerous cross-series 

 of spines or pectinae, the number being commonly about fifty; a rather long 

 distal region or tip is free from pectinae. At the widest part the full-sized noto- 

 podial setae have twice, or slightly more, the maximum diameter of the ventrals. 

 The most dorsal are longest and have a length (free portion) as great as the 

 length of the corresponding neuropodials or nearly so. (Plate 1, fig. 9). The 

 neuropodial setae are long and fine, and present a long smooth shaft, a pecti- 

 nate distal division, and a smooth, acute, bifurcate tip as usual. They are not 

 of the same structure throughout the fascia, in each of which there may be 

 from thirty-six to forty or more setae. The more dorsal and more nimierous 



