AGLANTHA. 121 



from the Maldive Islands (: 04) under the name A. octagona. There are 

 eight otocysts. 



The specimens were all colorless. 



The present captures, together with those already recorded by Agassiz 

 and Mayer ('99, : 02), show that Aglaura hemistoma occurs commonly over 

 the entire Tropical Pacific. It is already known from both sides of the 

 Atlantic, both Tropical and subtropical, from the Gulf Stream, from the 

 Gulf of Mexico, the Mediterranean, the Indian Ocean, and from the Ma- 

 laysian region (A. prismatica Maas, : 05, : 06°). Thus it is an inhabitant of 

 the warmer regions of all oceans. It is unknown, however, in cold seas. 



Aglantha Haeckel, 1879. 



Trachynemidae with long peduncle ; the gonads situated on the oral wall 

 of the subumbrella surface, not on the peduncle with either four or eight 

 otocysts. 



This genus has recently been revised by Maas (: 06 d ), to whose work I 

 refer the reader for a full account of its rather confused synonymy. From 

 his studies, as well as from those of Browne ('97), Chun ('97), and VanhdfFen 

 ('97), it is now clear that it contains at least two well-defined species, A. digi- 

 tate Fabricius and A. rosea Forbes, of rather different geographic range. The 

 first of these, distinguished by large size and by the possession of only four 

 otocysts, is of circumpolar distribution (Chun, '97). Within it three geo- 

 graphic varieties, A. occidentals (Maas, '93), A. digitate, and A. camtschatica 

 (Brandt, '38; Birula, '96), can be distinguished. 



A. digitate occurs throughout the arctic zone of the Atlantic, A. occidentalis, 

 in the northwestern Atlantic, from the Banks of Newfoundland south at least 

 as far as the northern margin of the Gulf Stream (A. Agassiz, '65 ; Hargitt, 

 : 05 b ), and A. camtschatica, so far as is known, only in Behring Sea and on the 

 northwest coast of America. A. rosea Forbes, with eight otocysts (Browne, 

 '97), is a much smaller species. The recently described A. conica (Har- 

 gitt, :02) is apparently a synonym of this form, which is of boreal or 

 temperate occurrence, being known from the British coast. Heligoland 

 (Ilartlaub, under the name A. digitalis), coast of New England (Hargitt), 

 and from Norway, where its range overlaps that of .1 digitate. Up to the 

 present time the genus has been known only from northern, if not actually 

 subarctic regions. But since the « Albatross" collection contains a consider- 



