NO. 9 



MARINE INVERTEBRATES, ALASKA — MacGINITIE 



41 



Developing worms were found in the egg capsules of the leech 

 Crangonohdella murmanica Selensky on October 11, 1949. Would 

 these emerge during the winter or would they remain in the capsules 

 and emerge about the beginning of the open season? Three species 

 of cumaceans were found with eggs in the marsupiums in September 

 and October, and a number of amphipods were ovigerous during the 

 winter (see table 4 for data). Numerous amphipods, certain isopods, 

 and the mysid Mysis oculata were carrying freshly deposited eggs 

 about the middle of October or later. 



The fact that the clam Cardita crassidens had large eggs within its 

 dorsal mantle cavity on October 11, 1949, suggests that this clam 

 broods its eggs during the winter and releases young clams at the 

 beginning of the open season or before. That the tunicate Dendrodoa 

 grossularia, which was found filled with large eggs on October 6, 1949, 

 also broods its eggs during the winter and releases large larvae at the 

 beginning of the open season is also a possibility. 



Data obtained on the eggs and breeding seasons of the animals are 

 included in the discussion of the various groups of animals beginning 

 on page 115. However, the principal information there presented is 

 summarized in table 4, below. In some instances too few animals of 

 a species were taken to provide information on the breeding season. 

 In other instances the impossibility of identifying the animals pre- 

 vented the keeping of records. When all the animals collected are 

 identified, future workers will be enabled to keep more complete 

 records on habits and breeding seasons. 



Table 4. — Data on eggs and breeding seasons 



Animal '^"*" "~- 



Coelenterates : 

 Hydroids 

 Hydracttnia sp. 

 Corymorpha sp. 

 Garveia sp. 

 Sertularella sp. ? 

 Sertularia sp. 



Thuiaria elegans 



T. lonchitis ? 



Hydromedusae 



Bougainvillea superciliaris 



Rathkea octopunctata 



