CUNINA GLOBOSA. 57 



of MetschnikofF ('86 a ), and more recently of those of Stchelkanowzew (: 06), 

 which have resulted in the demonstration that an alternation of genera- 

 tions of medusae occurs among the Narcomedusae. Haeckel ('80, p. 652) 

 has rather cavalierly referred it to C. vitrea, and Uljanin ('76) to C. laiiventris. 

 Metsclmikoff, however, in a more recent publication fS6 b ), argues that this is 

 not the case, and Stchelkanowzew (: 06), who has been able to study a large 

 series of C. proboscidea, has given evidence that it is a valid species. He bases 

 this conclusion chiefly on two characters, — the short, club-shaped otoporpae, 

 very different in outline from the long, narrrowly-oval otoporpae of C. laiiven- 

 tris, and on the presence, in sexually mature individuals as well as in small 

 specimens, of a marked proboscis supported by a pronounced prominence 

 of the gelatinous disc which he likens to the " Stiel " of the Geryonidae. 

 Since Stchelkanowzew has had a very favorable opportunity to study this form, 

 we will do well to accept his conclusion that C. proboscidea is distinct. 



Finally, we have the case of C. duplicaia Maas. This species has recently 

 been referred by Maas (: 04°, p. 34) to the family Aeginidae. But his orig- 

 inal figures ('93, taf. 5, figs. 9, 10) show clearly that the gastric pockets are 

 undivided, and equal in number to the tentacles, as is characteristic of the 

 Cunanthidae, while the large number of radial parts (sixteen) and the pres- 

 ence of otoporpae show that it is a typical Cunina. Maas ('93, p. 52) 

 believes that it has a determinate number (sixteen) of radial parts, and if 

 this should prove to be the case, it would require, as he suggests, the estab- 

 lishment of a new genus ; but, since he was able to examine only a single 

 specimen, it is not safe to assume the validity of this supposed character. 



All the foregoing species agree in the possession of a well-developed 

 peripheral canal system, at least in the primary generation. A form in the 

 present collection, however, entirely lacks these structures and must there- 

 fore be regarded as a new species. 



Cunina globosa Kscbscholtz. 



Cunina globosa Eschscholtz, '29, p. 117, taf. 9, fig. S ; Haeckel, '79, p. 319. 

 ? Aegineta globosa Gegenbaur, '56, p. -<>:5, taf. 10, iig. .S'. 



Plate 15, Fig. 3; Plate 17, Figs. 3, 8. 



Station 4546 Hyd. ; surface; 4 specimens, all about 15 mm. in diameter. 

 These specimens agree with Eschseholtz's account in general form, in 



