polynOe squamata. 203 



ridges, like those of the short setn?, but toward the middle 

 [F) these ridges appear to encircle the blade completely, as- 

 suming the aspect of so many closely-imbricated concentric 

 scales, before finally becoming obsolete upon the extremity 

 of the seta. 



The neuropodial aciculum needs no special notice, except 

 that the extremity of its trichophore projects as a sort of 

 papilla, less obvious in full-grown specimens, which divides 

 the neuropodium into an upper and a lower portion, the for- 

 mer containing about half as many setae as the latter. The 

 apertures of the trichophores are placed between lobe-like 

 prolongations of the neuropodium, to which the special term 

 of labia (Grube) may be applied. In this species they pre- 

 sent no remarkable peculiarity beyond their inequality. 



The neuropodial seta3 (Fig. 52, C, U), although at first 

 sight very different from the notopodial seta% are, in truth, 

 constructed on essentially the same plan, the blade being- 

 short, while the handle is proportionally elongated. The 

 blade is subcylindrical at its base, pointed and slightly curved. 

 Eight or nine transverse ridges extend around about two-thirds 

 of the circumference of its proximal half ; the basal ridges 

 are narrow, and merely serrated, but toward the apex the 

 ridges become deeper, and the serrations pass into strong 

 teeth ; at the same time, one side of the ridge is elongated 

 into a strong point. 



Attached to the under surface of the parapodium by a 

 somewhat enlarged base, with Avhich it is articulated, is a 

 smooth, conical, very flexible filament — the neuropodial cir- 

 rus (Fig. 51, c') ; it hardly reaches to the end of the neuro- 

 podium. Again, springing from the neural surface of the 

 somite, close to the parapodium, there is a small pyriform 

 tubercle (A), divided by longitudinal grooves into abovit eight 

 segments. This is possibly connected with the reproductive 

 function. 



The appendage of the notopodium, or rather of the noto- 

 podial side of the parapodium and somite, varies according 

 to the particular somite which may be examined. In some 

 somites this appendage is a cirrus (Fig. 51, D^ c) similar to 

 the neuropodial cirrus, but much larger, equaling the semi- 

 diameter of the body in length, and presenting an enlarged 

 pigmented bulb of attachment to which the filament of the 

 cirrus, which is cylindrical for about two-thirds of its length, 

 and then becomes enlarged and suddenly tapers to its extrem- 

 ity, is articulated. 



