HALF AN HOUR WITH CORALLINES. 



89 



confusion which exists, by reason of different zoolo- 

 gists having given different names to the same 

 species. Let us commence with one Fig. 37 



of these Sertularians, the "Bottle- 

 brush Coralline" (Thuiaria thuia, 

 Fig. 37). As is shown in the wood- 

 cut, this species is usually found 

 attached to shells in tolerably deep 

 water. The cells or calycles are 

 imbedded in the substance of the 

 branches, as shown in Fig 38, the 

 capsules being pear-shaped and 

 smooth. A species nearly allied to 

 it is the T. artieulata, known by its 

 more feathery appearance. 



The "Sickle Coralline" (Hydrall- 

 mannia falcata, Fig. 39) is so called 

 on account of the appearance pre- 

 sented by the arrangement of the 

 cells on one side of the curved 

 branches only. This genus formerly 

 went by the name, of Plumularia, 

 under which the student will find 

 it in the older works on hydrozoa. 

 It is a very common, but exceedingly 

 elegant species, about six inches in 

 height, having slender branches 

 which twist about in a spiral manner. Thuiaria thuia, 

 The cells containing the polypites 

 are arranged along those branches. It is usually 



