414 THE AUSTRALIAN HYDROMEDUS.E, 



SERTULARIA RIGIDA. Lamouroux. 



This species has been found in Australasia and described by 

 Lamouroux (1). It has been also mentioned by Blainville (2) ; 

 Lamarck (3), speaks of it as Sertularia divaricata. 



SERTULARIA DISTANS. Lamouroux. 



This species was found by Lamouroux (4) in Australasia and 

 described by him. It has also been mentioned by Lamarck (5.) 



SERTULARIA TRIDENTATA. Lamouroux. 



This species was found in Australasia by Lamouroux (6), and 

 mentioned by Lamarck (7.) 



SERTULARIA SCAN DENS. Lamouroux. 



This species found in Australasia has been described by 

 Lamouroux (8), and also mentioned by Blainville (9.) De 

 Lamarck (10) speaks of it under the name of Sertularia millefolium. 



3. GENUS. DIPHASIA. A. Agassiz. 



Branching colony, trophosoms opposite a pair on each Internode 

 or alternate. They possess an internal operculum. Polypostyles 

 different in the two sexes. 



DIPHASIA SYMMETRICA. Nov. sp. 



Plate VIII, Fig. 7. 



Shoots rather irregularly pinnate. Stems tapering towards the 

 centrifugal end. Hydrothecce opposite, standing at an angle of 



(1 ) Lamouroux. Histoire des Polypiers Coralligenes flexibles, p. 190. 



(2.) Blainville. Manual d'Actinologie. 



(3.) Lamarck. Histoire Naturelle des aminaux sans Vertebres. 



(4.) Lamouroux. Histoire des Polypiers Coralligenes flexibles, p. 191. 



(5.) Lamarck. Histoire Naturelle des animaux sans Vertebres. 



(6.) Lamouroux- Histoire des Polypiers Coralligenes flexibles, 187. 



(7.) Lamarck. Histoire Naturelle des animaux sans Vertebres. 



(8.) Lamouroux. Histoire des Polypiers Coralligenes flexibles, p. 189. 



(9. ) Blalnvillle. Manual d'Actinologie. 



(10.) Lamarck. Histoire Naturelle des aminaux sans Vertebres. 



