158 THE MEDUSAE. 



[Phialidium temie Browne, :04) and Oceania car olinae Mnyer (: 00°). These 

 two are clearly separable by the number of marginal organs ; for though 

 the number of tentacles and tentacular bulbs is variable, they are con- 

 siderably more numerous in P. rireiis than in P. carolinae, while the number 

 of otocysts in the former is only about one half as great as it is in the 

 latter. P. carolinae has been recorded but once, from Charleston, S. C. ; 

 while P. rirens is now known to be widely distributed over the Indian 

 Ocean and Malaysian region (Bigelow, : 04, Browne, : 04, Maas, : 05, : 06°), 

 and it is perhaps the same species as Mitrocoma mhengha which was 

 described by Agassiz and Mayer ('99) from the Fiji Islands. The present 

 collection contains a series referable to this same genus, but differing in an 

 important character, i. e. presence of cirri, from both P. virens and P. 

 carolinae. This species is, however, closely allied to, if not identical with, 

 certain specimens from the Island of Guadaloupe, West Indies, in the 

 collection of the Museum of Comparative Zoology, and is apparently 

 undescribed. 



Phialucium comata, sp. nov. 

 Plate 5, Figs. 6, 7 ; Plate 6, Fig. 9 ; Plate 37, Figs. 9, 10, 13. 



Acapulco Harbor ; surface ; 5 specimens, 3 mm. to 6 mm. in diameter. 

 Type 6 mm. in diameter (also Guadeloupe Island, West Indies; surface; 

 9 specimens, 3.5-12 mm. in diameter). 



In general outline the bell is high (PI. 5, fig. 7), the gelatinous substance 

 thick, and the umbrella cavity deep. In none of the Pacific specimens is 

 there any trace of peduncle or even any swelling of the gelatinous sub- 

 stance at the point where the manubrium is situated. The same is true 

 of the West Indian specimens from 3 mm. to about 9 mm. in diameter ; 

 but in the largest, 12 mm. in diameter, the manubrium is situated on 

 a broad but very low swelling. This, however, is not sufficiently pro- 

 nounced to warrant referring the species, on the ground of its possessing 

 a distinct peduncle, to Eirene. 



The only difference between the Pacific and the West Indian specimens 

 is afforded by the number of tentacles and tentacular knobs. In the 

 largest specimen frotn Acapulco there are seventeen tentacles and twenty- 

 three knobs; in the smallest, eight tentacles and eight knobs; but in 

 specimens of corresponding sizes (6 mm. and 3 mm.) and stages of develop- 

 ment from the Atlantic the number of knobs is considerably greater, there 



