THE ANNALS 



AND 



MAGAZINE OF NATPEAL HISTOllL 



[SEVENTH SERIES.] 

 No. 120. DECEMBER 1907. 



LXIV. — A Revision of the Medusce belonging to the Family 

 Laodiceidae. By Edward T. Beowne, University 

 College, London. 



This is an old family-name to which I have given a new 

 definition. Although the character selected is a conspicuous 

 one, it has not hitherto taken an important position in classi- 

 fication, but has been chiefly used as a character for distin- 

 guishing certain genera. This character, now selected for 

 the family, is the presence of cordyli, commonly called 

 sensory clubs, on the margin of the umbrella. 



Some of the genera which possess cordyli were placed by 

 Hccckel amongst the Thaumantidae, of wiiich the Laodiceida3 

 formed a subfamily, and was distinguished from the other 

 subfamilies not by the presence of cordyli, but by the number 

 of radial canals. The other genera, on account of their 

 having branched radial canals, were placed in the Cannotidce, 

 a family which Maas (1904) has recently revised. 



In the family Laodiceidaj I have placed the following 

 genera : — Laodice, Staurojyhora^ Ptychogena^ Staurodiscus, 

 Toxorchis, and Melicertissa. The characters of these genera 

 have been revised, but the revision has not led to a trans- 

 ference of species. The species of all the genera have been 

 subjected to an impartial examination, which has resulted in 

 a reduction of their number. For the pur[»ose of making 



Ann. cfc Mag. N. Hist. Ser. 7. Vol, xx. 30 



