BIGELOW: COAST WATER EXPLORATION OF 1913. 313 



are more branched than usual, so much so, that if they were examined 

 by themselves they would scarcely be recognized as belonging to the 

 species. The branching sometimes is far from being regular, the 

 position and the length of the branches vary so much. From a stem 

 that is otherwise normal, there may be one or two hydrothecae borne 

 on much elongated pedicels, arising either as ordinary hydrotheca 

 pedicels, or in the axils of these. They are annulated slightly at both 

 ends as well as towards the centre, with smooth places between 

 (Fig. 76). The stem internodes, which typically are quite imiform in 

 length, vary much in this respect in some specimens and the nature 

 of the geniculation at each node also varies. The terminal internode 

 may be much prolonged into a tendril-like process such as occurs late in 

 the season in Campanularia angulata, Obelia commissuralis, and other 

 similar species. These tendrils are noticeable chiefly on account of 

 their breadth and the bluntness at the end (Fig. 77). Within the 



Fig. 77. — Obelia geniculata. 



perisarc, at the end, the coenosarc has the appearance of a developing 

 hydranth but no case was observed where such a hydranth had really 

 developed. 



In a previous paper ^ I referred to a specimen of this species in which 

 the gonophores were in an unusual position. In this material a still 

 greater variation occurs. Some gonophores are placed typically, i. e., 

 in the axils of the hydrotheca pedicels. Others appear as those in 

 the above reference, i. e., in place of hydrothecae (Fig. 76). Besides 

 these there were several in a row growing directly from the stolon 

 (Fig. 78). They have similar short, annulated pedicels to those in 

 the normal position and agree very well with them in other respects, 

 although they are slightly larger than the others usually are. The 

 development has not been stopped at any rate, as the young medusae 

 were in as good condition as they were in any of the others. If the 



1 Hydroidsfrom Nova Scotia. Victoria Memorial Museum, Bull., 1913, no. 1, p. 167. 



