70 BRITISH HYDROID ZOOPHYTES. 



opposite. The receptacles are tubular and 

 opposite ; the capsules are ovate, tapering to 

 a short pedicel. There is a slight collar to the 

 aperture. Very common. 



Sertularia gracilis, Hassan. 



1 dry specimen, and 1 specimen in box. 



specimens A species of particularly fine 

 49, 50. habit. It is symbiotic on other 

 hydroid stems, over which it grows, throwing 

 up short and fine stems. The receptacles are 

 opposite and tubular, the rim being sharp. 

 The female capsule is ovate with a narrow 

 collar-like aperture. They may be seen on 

 the specimen in the glass-topped box. 

 Not common. 



Sertularia operculata, Linnaeus. (Plate VI.) 



2 dry specimens, and 1 specimen in box. 



specimens T ue stem of this species is very 

 51, 52, 53. delicate, branches distantly in a 

 dividing manner, and produces colonies of 

 enormous extent, and luxuriant in growth. It 

 has been called the " sea hair" hydroid. The 



