62 THE ANNELIDA POLYCHAETA. 



The prostomium is covered above by the transparent first and second 

 elytra. It is trapeziform or subhexagonal with the transverse diameter or width 

 exceeding the length. It is widest a little behind the middle where it bulges 

 on each side. Upon the bulging lobe on each side is borne a large eye. The 

 posterior eyes are much smaller and closer together and each is close to, and in 

 life may possibly be covered by, the base of the parapodium of the first meta- 

 stomial segment. The ceratophore of the median tentacle is inserted in an 

 incision in the middle of the anterior border; its base extends caudad in a narrow- 

 ing, wedge-shaped process; it narrows subconically distad to the truncate end, 

 on which is inserted the style; the style is long, though it is shorter than the 

 palps, fully three times as long as the prostomium; it narrows continuously 

 from the base to the slender and acute tip; without any evident subterminal 

 enlargement; the ceratophores of the lateral tentacles are inserted farther 

 forward; each is subcylindrical, but narrows distad like the median; the distal 

 end of the ceratophore is much thicker than the base of the style; the style is 

 shaped like that of the median tentacle but is shorter. The tentacles are pale 

 without any evident darker markings in the type as at present. The palpi are 

 a little longer than the median tentacle; each is terete and acuminate, and ends 

 in a slender thread-like tip. (Plate 5, fig. 4). 



The ceratophores of the parapodia of the peristomium extend forward about 

 to the level of the anterior border of the head; the styles are of the form of the 

 tentacular styles but are somewhat longer than the median of these. 



The extended proboscis is 4.2 mm. long and 2.5 mm. thick. 



The metastomial somites are distinct. They are of similar form and 

 structure throughout. The pygidium is minute and subcylindric ; anus terminal. 

 The nephridial papillae are situated on the bases of the parapodia; each is borne 

 at the caudal edge and is a slender, cylindrical tube of white color which bends 

 dorsad in the intersegmental cleft. 



The parapodia in the anterior region are only half, or but little more, the 

 width of the body proper; but in the median and posterior regions they fully 

 equal the width of the somites to which attached. From the base outward 

 they are subcylindric or slightly narrowing distad, the distal end conically 

 attenuated and rounded. At the distal end is a larger, distally rounded, postsetal 

 process and a much more slender, cylindrical, presetal process, the setae emerging 

 between these processes. The notopodium appears on the anterior parapodia 

 as a short and -slender cylindrical process into which an aciculum extends; this 

 becomes lower caudad and in most segments is not evident as such. The 



