SOME NEW SCYPHOMEDUS.E OF JAPAN. 15 



Those on the axial side of each two oral arms unite in perradial 

 planes and form four perradial wings of sucking frills. The 

 wings are very short (fig. 12). At each junction of the oral 

 suture (" Pfeiler-gabel " of Haeckel) there hangs down an ap- 

 pendage of very large size. 



The subgenital cavity lies between the umbrella and the oral 

 disc. It is divided into four large lobes, separated from one 

 another by as many long perradial septa. The length of each 

 septum is about three-eighths the greatest breadth of the cavity. 

 We do not find crucial gelatinous thickenings continuous to these 

 septa. The gastrovascular membrane is not loose. There are 

 four interradial gelatinous ridges which run directly from the 

 lower lip of the subgenital Ostia. The latter are very small and 

 of crescent shape. 



The oral arms are short, thick and stout. They belong to 

 a primitive type of the three-winged arms and show many charac- 

 teristic features. They are shorter than the umbrella radius and 

 do not project out of the umbrella margin. The upper arms are 

 nearly coalesced and form a large part of the octagonal oral disc. 

 The upper arms project from both sides of the oral disc, axially 

 as well as abaxially. The lower arms are also very short, being 

 of nearly the same length as the upper arms. The axial wing 

 of the oral arms is very well developed, giving out a profuse 

 quantity of branches which completely cover the axial portion of 

 the oral arm. The abaxial wings are wide ; they are developed 

 upwards. Appendages of the oral arms are very long, numerous 

 and circular in cross-section. There are from six to eight of 

 them on each abaxial wing ; much more numerous are they on 

 the axial wing. They are canalled and many of them are longer 

 than the umbrella diameter. Specially long and large appendages 



