HYDROMEDUSAE 269 



to find a few very early stages not seen by Mr Browne; in order to facilitate under- 

 standing of the interesting development of this species I have divided the specimens into 

 three groups according to the number of main radial canals, and the description of the 

 development is revised in accordance herewith and considerably augmented, (vi) The 

 tentacles of Tiaricodon coeruletis are described somewhat more thoroughly than in the 

 original manuscript. 



The species all belong to the order Leptolina, comprising the three suborders 

 Anthomedusae, Leptomedusae and Limnomedusae. The third of these suborders was 

 recently established by me, and before it was published I told Mr Browne about it in a 

 letter, which reached him ten days before his death. The Limnomedusae (Kramp, 

 19380, p. 107 and 1938Z), p. 57) originally comprised the two families of Hydromedusae : 

 Moerisiidae (formerly reckoned among the Anthomedusae) and Olindiidae (formerly 

 considered by most authors as belonging to the Trachymedusae). Later on I found 

 (Kramp, 1939, p. 503) that the family Williidae belonged to the same suborder, and in 

 the present paper this much discussed family is placed where in my opinion it belongs. 

 I also found that Tiaricodon coertdeus is closely related to Moerisia and Caspionema and 

 accordingly should be referred to the family Moerisiidae. 



The zoogeographical interest of the medusoid fauna of the Falkland Islands and its 

 marvellous resemblance to the medusoid fauna of the British seas had already been 

 emphasized by Mr Browne in his preliminary report (p. 274) and has become even 

 more evident through the increase of our knowledge of related species and their 

 distribution and classification. With very few exceptions the specimens were collected 

 in Stanley Harbour. The material is now in the British Museum (Natural History) in 

 London. 



The figures are reproduced from Mr Browne's own beautiful drawings, except those 

 on Plate XIX and the following figures in the text : Fig. i {Phialella falklandica) and the 

 diagrams Figs. 2, 3, dF, ja, and yb of Willia mutabilis. 



P. L. KRAMP 

 Copenhagen, 

 3 April 1939 



