312 THE ANNELIDA POLYCHAETA. 



Peristomium well developed. Seven eighths or more the length of somite 

 II and about two thirds as wide. Lower lip longitudinally rugose. 



Somite II, conspicuously larger than I and extending forwards and embrac- 

 ing the sides of the latter, its large parapodia well forward. Subdivided dorsally 

 by a weak transverse furrow, the caudal division the shorter. The next seven 

 to ten somites very gradually decrease, the somites over the middle region remain- 

 ing nearly equal, short, the ratio of length to width being only about one to ten 

 or eleven. At the caudal end the somites become still shorter. 



Parapodia, excepting anterior pairs, not prominent. Parapodia of somite 

 II, as usual, much the largest. These project obliquely ventrocephalad, extend- 

 ing ventrad much below the general ventral surface of the body and forwards 

 to near the level of the anterior end of the prostomium; narrowing distad, tip 

 compressed in an oblique direction and with a conspicuous, slender, finger-like, 

 or cirriform, postsetal process. Notocirrus near middle, this a simple style with- 

 out differentiated cirrophore and not reaching end of parapodium. Neuro- 

 cirrus similar to notocirrus but shorter, attached on ventral surface proximad of 

 the middle. The second parapodia (on somite III) are decidedly shorter and 

 less stout than the first, but are still much larger than the following ones. They 

 project conspicuously obliquely cephaloventrad in a direction parallel to the 

 first ones. The notocirrus is longer, passing the tip of the parapodium. The 

 postsetal process is also longer, reaching to the distal end of the setae, in the 

 form of a slenderly triangular, compressed process furrowed along the middle 

 of both surfaces. The neurocirrus is proportionately longer and attains, or very 

 nearly attains, the end of the parapodium. The third parapodia are still shorter 

 and project more horizontally. The notocirrus is longer, exceeding the para- 

 podia and attaining the tips of the seta. The neurocirrus is stouter and shorter, 

 subcorneal. The postsetal lip is of the same form and size. The fourth para- 

 podia are of essentially the typical form and in the typical position. They are 

 a little shorter and distally blunter than the preceding. In none of the para- 

 podia is there a distinct presetal lip. The postsetal processes remain large 

 and of nearly uniform length back to about the twelfth or fifteenth somite, and 

 then become gradually reduced to slight, pale papillae, in the caudal region 

 being scarcely evident. The neurocirrus is still shorter and more bluntly rounded 

 on the fifth parapodia, on the sixth is abruptly reduced to a slightly elevated broad 

 papilla, and on succeeding ones is further reduced and merged in a low, glandu- 

 lar swelling at base of parapodia, these glandular areas becoming shorter 

 caudad. With the appearance of the branchiae the notocirri become much 



