204 THE ANNELIDA POLYCHAETA. 



of the body, is deep dorsoventrally and of moderate length. It presents four 

 subcorneal lobes, of which the two submedian ones project distinctly farther 

 distad than the others. The dorsal lobe presents a swollen basal region of con- 

 siderable size, from the dorsal edge of which the slender notocirrus arises and 

 from the anterior side of which the large, basally much inflated, distally conical, 

 process extends forwards. The notocirrus, which is slenderly tapered distad, 

 extends to or, more commonly, clearly beyond the distal end of the main conical 

 dorsal lobe. The ventral lobe arises near the base of the parapodium, extend- 

 ing first ventrad and then bending distad at right angles to its basal portion. 

 It is subconical, but is more or less abruptly reduced in diameter near the middle 

 of its length. The neurocirrus is attached at the extreme base of the parapodium, 

 extending ventrad in the narrow space between the ventral lobe and then curv- 

 ing distad. It is slightly more slender than the notocirrus. The notopodium 

 is a short lobe having an oblique distal surface, with the lower angle protruding 

 distad into a conspicuous conical process, at the dorsal edge of the base of which 

 the aciculum emerges. This lobe extends as a low ridge or presetal membrane, 

 a slighter one being present as a postsetal lobe. The neuropodium is a little 

 less thick than the notopodium. At the distal end it is similarly produced into 

 a conical lobe caudoventrad of the setae. The aciculum extends into the upper 

 part of the process, emerging from its dorsal surface. The expansion of the 

 dorsal lobe from which the style of the notocirrus arises becomes reduced in the 

 most anterior parapodia, in the first pair appearing as an ordinary cirrophore. 

 (Plate 32, fig. 5). 



There are two acicula in each parapodium, one in each ramus. They are 

 dense black in color, and taper to a slenderly acute tip. The neuropodial acic- 

 ulum curves conspicuously ventrad, entering the distal neuropodial process 

 and running beneath its dorsal surface to the point of emergence. The noto- 

 podial aciculum curves dorsad, emerging at the base of the distal process. The 

 setae of the neuropodial fascicles are much more numerous than those of the 

 notopodial and are obviouslj^ longer. The setae are all compound and are of 

 two types. The notopodials are all of one type. These have slender shafts 

 which are strongly finely cross-striate, or camerated, and end in slightly widened, 

 symmetrical, or homogomphus, sockets. The apical piece, or blade, is long, 

 tapering to a fine tip, and is fringed densely along one margin proximad of the 

 smooth tip. In the neuropodium the more numerous setae are of the same type 

 as those of the notopodium; but in the ventral part of the fascicle are a number 

 of setae of a second type. These have stouter but similarly strongly camerated 



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