1911.] NATURAL SCIENCES OF PHILADELPHIA. 253 



large, conspicuous, brown, situated close to the posterior border 

 immediately behind the lateral tentacles. Tentacles five, arising 

 along a slightly curved transverse line near the posterior end of the 

 prostomium, but passing in front of the eyes laterally. All slightly 

 fusiform, tapered to distal end and transversely wrinkled or subar- 

 ticulated, the median about one and one- third times the length of the 

 prostomium, the others successively somewhat shorter. 



Peristomium a simple, regularly cylindrical, smooth, apodous ring 

 with a slight median ventral notch on the lip and no trace of nuchal 

 cirri. Somite II scarcely more than one-half as long as I, but otherwise 

 similar. The remainder of the body is terete, of nearly uniform 

 diameter except that the posterior portion is somewhat enlarged and 

 distended with ova. The segments become shorter to the branchial 

 region, where they are about four and one-half times as wide as long; 

 posterior to this the length again increases until at the posterior end 

 they are only twice as wide as long. With the fourth (PI. XVI, fig. 29) 

 a small ring separates at the anterior end of each segment and increases 

 until in the post-branchial region it forms a regular propodal annulus. 

 Pygidium at the end of the regeneration cone a short tube bearing one 

 cirrus about equal to one-fourth the body width and another half as 

 long as the first. 



Parapodia (PI. XVI, figs. 30, 31) strictly lateral and in the pro- 

 branchial and branchial regions prominent and outstanding, becoming 

 smaller in the postbranchial region, strictly uniramous, there being 

 no trace of a notopodium. Anterior parapodia consist of a low, 

 rounded, slightly compressed setigerous tubercle, behind which is a 

 compressed postsetal lip at the base as deep as the setigerous lobe, 

 while its bluntly ending dorsal part is prolonged to about twice the 

 length of the base. The notocirrus arises just above the foot and is 

 about twice its length, somewhat enlarged at the base, slender and 

 tapering distally and marked with obscure annular furrows. The 

 neurocirrus has a thick, swollen base broadly attached to the ventral 

 face of the neuropodium and bearing a small papilliform distal piece 

 which is bent more or less ventrad. Posterior to the branchial region 

 the parapodia and all of their parts become gradually smaller. The 

 neuropodia become low, compressed cones (fig. 31), the apex of which 

 is formed by the acicular process, while the postsetal lip becomes low 

 and inconspicuous. The basal part of the neurocirri is much reduced, 

 leaving only the short, bluntly rounded cirrus which reaches to the 

 end of the acicular process. The notocirrus while undergoing reduc- 

 tion in size retains its characteristic form and proportions, having a 



