Gatiy Marine Laboratory ^ St. Andrews. 183 



bristled feet (PI. VIIF. fig. 8), the latest stage observed 

 towards the end of May. 



If the young Nereids of the foregoing stages are left in tlie 

 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 17th July the young forms are found on the same 

 sites, but considerable progress has been made in develop- 

 ment. The head in outline nearly resembles that of the 

 adult and is marked by whitish pigment in front of the eyes 

 in the smaller, brownish in the older, which are definitely 

 formed on each side, the anterior pair being somewhat larger 

 and furnished with lenses. The frontal tentacles and the 

 palpi are well formed and show numerous fine palpocils, the 

 mobility of the distal segment of the palpi being noteworthy. 

 The two pairs of tentacular cirri are now much longer, the 

 dorsal stretching outward like fine hairs as the animal pushes 

 its snout forward. They retain the proportions to each other 

 of the adult, though they have not yet reached full develop- 

 ment in any case. The ventral of each is considerably 

 shorter than the dorsal, but projects clearly on each side, the 

 first rather longer and thicker at the base than the frontal 

 tentacles. The body is now elongated, having from sixteen 

 to twenty bristled feet, and is marked along the centre by a 

 yellowish or brownish streak, often slightly moniliforra or 

 zigzag from the intestinal contents, and a whitish dot is 

 observed in some at the bases of the feet. The massive and 

 somewhat ovoid proboscis has six teeth behind the great 

 anterior fang, and the narrow part of the canal behind it is 

 usually firmly contracted (and empty). The first part of the 

 gut behind the post-proboscidian narrow region is the largest, 

 and for some distance it is not marked by lateral constrictions, 

 as in the succeeding portion. Most of the feet anteriorly 

 present a condition approaching that of the adult, though the 

 dorsal cirrus is shorter. Only the last two feet are devoid of 

 bristles externally. The caudal cirri are now considerably 

 longer. The circulation of the red blood in the dorsal and 

 ventral trunks is now evident. The segmental organs 

 extend backwards to the posterior feet, though not quite to 

 the tail. 



So far as observed at St. Andrews, therefore, there is no 

 foundation for the statement that the Scotch representatives 

 are hermaphrodite, and still less that they are viviparous, as 



