112 G. A. ELRINGTON 



SUMMARY. 



1 . The larval Polychœta described in the foregoing pages is the same 

 as the larva originally described by Claparede under the name Terebella 

 conchilega. 



2. The view expresses by Giard that this organism is not a larval 

 but an adult annelid, belonging to a distinct group, is based upon a mis- 

 interpretation of a certain structure, described by us as the dorsal gland. 

 The name Wartelia gonotheca given to this larva by Giard should be 

 abandoned. 



3. The so-called brain-cells which Claparede observed, and which 

 were asserted to be ova by Giard and Nordenskiold are in reality glan- 

 dular, and form a dorsal gland. The sécrétion of which is used in the for- 

 mation of the transparent tube which the larva inhabits. 



The dorsal gland is a teraporary organ which disappears when the larva 

 abandons its pelagic inhabits and commences to construct its sandy tube. 



4. The larvse were found to possess three separate pairs of nephridial 

 ducts. No nephrostomes are présent. The relation of thèse larval nephridia 

 to those of the adult has not been established. Further investigations are 

 required on this point, in order to décide whether the adult nephridium is 

 a new structure, or formed by the coalescence of the larval nephridia. 



