JAPANESE PALOLO, CERATOCEPHALE OSAWAI, N. SP. 13 



sometimes the second or the fourth — is of a somewhat more 

 complicated structure, being supplied with the acicula and the 

 bristles in both rami. Especially the ventral ramus is more 

 strongly developed than in the preceding parapodium. The ligula 

 is larger, and extends a little beyond the ends of the terminal 

 lobes of the ventral ramus. The dorsal cirrus differs from that 

 of the first parapodium in that its basal section is longer and 

 takes up nearly one- third of the entire length. 



The series of successive parapodia beginning with the one last 

 described and reaching down to about the 150th or thereabout, 

 possesses essentially the same parts, which however show a very 

 gradual variation in the following manner : 



The distal portion of the dorsal cirrus grows relatively shorter 

 posteriorly to about the 100th parapodium, from which point 

 farther backwards it again becomes somewhat longer but more 

 and more slender. The basal section of the cirrus increases in 

 size posteriorly until about the 10th parapodium (Woodcut 2), 

 where it attains its maximum size, and thence backwards it again 

 gradually becomes shorter. The ligula continues to grow larger 

 but flatter until about the 20th parapodium, in which it attains 

 ils greatest size. From that point backwards it gradually becomes 

 smaller again. The setose bristles of the dorsal ramus are longest 

 in about the GOth parapodium, in which the blade is 2h times 

 as long as that of the same bristle in the 30th parapodium. 



The aciculse vary in length in proportion to the general size 

 of the parapodium to which they belong. Abnormally two or 

 three acicuhe may occur together in either of the two rami. 

 Such cases have been found most frequently in the first two or 

 three parapodia. 



The terminal lobes of the ventral ramus increase in size from 



