HYDROID FAUNA OF THE BERMUDAS. 



253 



onies of this hydroid, whose canaliculated coenosarc and unprotected 

 gonangia place it in the genus Aniennularia. The trophosome agrees 

 with that described by Nutting for A. pinnata, except that I was able 

 to find only one nematophore, instead of two, in the axil of each hydro- 

 cladium, and none at all on the stem, although Nutting states that 

 they are "scattered over the stem."^ There is also considerable dis- 

 parity in size between my specimens and his, but this is not conclusive 

 evidence of specific difference. Some of the colonies are sparsely 

 branched, and the arrangement of the hydrocladia is invariably alter- 

 nate or subalternate. 



FiGUKE 2. Antennularia pinnata. Portion of colony bearing male and 

 female gonangia. X 12. 



The gonangia (Fig. 2) are unprotected, oblong-ovate, coarsely and 

 irregularly annulated, about 20 times as long as the hydro thecae, with 

 strictly terminal apertures, and are borne singly on short processes 

 from the stem opposite the hydrocladia. Both male and female 

 gonangia are found in the same colony. The female blastostyle bears 

 usually a single gonophore, which is situated on one side. The male 

 blastostyle is entirely surrounded by the mass of male reproductive 

 cells. The position of the gonangia, their annulated walls, their 



1 Professor Nutting has kindly corroborated my identification of this species 

 and of Plumularia inermis. 



