HYDROMEDUSAE. 739 



There is only one specimen in the collection, and a figure is given of it because I am 

 not certain about the correctness of the identification. Liriope tetraphylla has, according to 

 Vanhoffen, a very wide geographical distribution, as it was found by the " Valdivia " in the 

 Atlantic, Indian Ocean, and the Red Sea. The specimens showed a considerable variation in 

 the shape and size of the umbrella, in the length of the peduncle, and in the position and 

 shape of the gonads ; all of which have been used by other authors for specific characters. 



Description of the specimen. Umbrella hemispherical, very thick, about twice as broad 

 as high. Stomach on a cylindrical peduncle. Gonads rhomboidal, broader than long, on the 

 distal half of the radial canals and extending nearly to the margin of the umbrella. The 

 distance between the gonads about equal to their breadth. Four perradial tentacles. Three 

 centripetal canals in each quadrant. Eight sense organs. 



Size. Umbrella 7 mm. in width and 4^ mm. in height. Peduncle 3 mm. in length. 



Locality. Indian Ocean ; Maldive Is. (Gardiner). 



Family Aglauridae, L. Agassiz, 1862. 



Trachomedusae with eight radial canals, in the course of which are situated eight gonads. 

 Stomach on a peduncle. Numerous uniform tentacles. Sense organs external and free. 



Genus Aglaura, Peron et Lesueur, 1806. 

 Generic Character. Aglauridae with gonads situated upon the peduncle of the stomach. 



Aglaura hemistoma, Peron et Lesueur, 1809. 



Aglaura hemistoma, Gegenbaur' (18.56, p. 248, Taf vii.); Haeckel (1879, p. 275, Taf xvi.); 

 Maas (1893, p. 25, Taf i.); Mayer (1900, p. 65, PI. XXV.); Vanhoffen (1902, p. 78). 



The collection contains a single small specimen, which is not in very good condition. 

 The shape of the umbrella is very much like that of the figures given by Haeckel and 

 by Mayer. 



Description. Umbrella with a short conical summit, about 2^ mm. in length and width. 

 Stomach roundish, on a very short peduncle. Mouth with four lips. Eight sausage-shaped 

 gonads, about 1 mm. in length, situated on the peduncle and adjacent to the stomach. Ova 

 visible. Tentacles estimated at about 64. Sense organs not seen ; the margin of the umbrella 

 is damaged. 



Distribution. In the warm waters of the Atlantic, Indian Ocean, and the Red Sea. 



Amphogona, genus novum. 



Generic Character. Aglauridae with gonads situated upon the sub-umbrella. Gonads 

 bisexual. Umbrella much broader than high. 



G. II. 95 



