322 NEREIS DIVBRSICOLOR. 



(opposite the eyes) is a short subulate process; that of the next segment is indistinct, 

 though, with the exception of the caudal cirri, the dorsal is the longest of the series. 

 The bristles of this segment are always short and in contrast with the next segment, 

 which shows the segmental organs immediately behind. Opacities in the corresponding 

 parts of the following feet indicate the early development of these organs throughout. 

 Traces of a fourth tooth behind the great anterior fang of the maxilla are visible. This 

 description might also apply to a post-larval form with eight pairs of bristled feet 

 (Tig. 74), the latest stage observed towards the end of May. 



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Fig. 74. —Young N. diver sicolor with eight pairs of bristled feet and four eyes. g. Glands of alimentary canal, 

 m. Maxillae, pal. Palpi, pg. Pygidium. pr. Proboscis, so. Segmental organ ?. 



If the young Nereids of the foregoing stages are left in the vessels beside the adults 

 the larger examples rapidly disappear. They are probably devoured by the adults, only 

 the minute stages escaping capture, and in all likelihood they, too, would by-and-by be 

 found out and captured ; yet, as in the fishes, these checks have little influence on the 

 permanent abundance of the species. 



On the 1 7th July the young forms are found on the same sites, but considerable progress 

 has been made in development. The head in outline nearly resembles that of the adult, 

 and is marked by whitish pigment in the younger, brownish in the older, in front of 



