BIGELOW: MEDUSAE FROM THE MALDIVE ISLANDS. 257 



Aglaura prismatica Maas. 



Aglaura prismatica Maas, 1897, Mem. Mus. Comp. Zool., vol. 12, p. 24, taf. 3. 

 Lessoiiia radiata ? Eydoux et Souleyet, 1841-52, Voyage du la 15onitc, vol. 2, 

 Zoophytes, plate 2. 



A species of Aglaura apparently identical with the Aglaura prismatica of 

 Maas was one of the most abiuidant Medusae in the tow. We took it at 

 almost every station, hotli inside and outside the atolls, often in large numbers. 

 All our specimens were quite colorless and transparent, a condition similar to 

 that observed by Agassiz and Mayer in several specimens from Fiji (Bull. Mus. 

 Comp. Zodl., vol. 32, p. 165, plate 4, fig. 13). 



Aglaura octagona, sp. nov. 



Plate 3, Fig. 9. 



The bell is distinctlj^ octagonal, lantern-shaped, and flattened at the top; it 

 is three mm. high, and about one half as broad. The walls, although exceed- 

 ingly thin, are very rigid, and the vellum is provided with a series of circular 

 nuiscles. There are about thirty-two tentacles, which in our specimens were 

 all broken short off, leaving stumps behind. The peduncle is three fourths as 

 long as the bell is high and cannot be retracted within the bell cavity. The 

 stomach is short and globular, and the mouth bears four simple lips, which 

 hang nearly on a level with the bell opening. The gonads are egg-shaped, and 

 are borne at the junction of the radial canals with the stomach. There are 

 eight interradial otocj'sts. The whole Medusa is perfectly colorless. 



Two specimens, December 30, off the east face of Kolumadulu atoll, in an 

 open net at about one hundred fathoms. Aglaura octagona is very closely 

 allied to Aglaura laterna Haeckel, from the Canary Islands. It differs, how- 

 ever, in the following particulars : The peduncle is longer, the gonads are egg- 

 shaped instead of spherical, and the tentacles seem rather more numerous. 

 (Aglaura laterna has usually from sixteen to twenty-four.) The form of the 

 bell in both species is identical, and in other general proportions they are veiy 

 similar. The genus Aglaura falls into two well-marked divisions, one repre- 

 sented by Aglaura hemistoma, with the closely allied varieties, prismatica 

 Maas, from the Pacific, nausicaa Haeckel and vitrea Fewkes, from the Atlan- 

 tic, characterized by the short peduncle; and the other represented by Aglaura 

 laterna Haeckel, from the Canaries, and Aglaura octagona, sharply distin- 

 guished by the long peduncle and lantern-shaped bell. I think it is probable 

 that these may all prove to be merely geographical races of two well-defined 

 species. 



Liriope Lesson, 1843. 



In the "Craspedoten Medusen der Deutschen Tiefsee-expedition," ]^. 79, 

 Dr. Ernst Vanhofl'en has "iven an able analvsis of this iienus which he, follow- 



