BIGELOW: MEDUSAE FROM THE MALDIVE ISLANDS. 261 



This form seems quite distinct from all other species of Pegantlia, to which 

 genus it undouhtedly belongs. Its two striking peculiarities are the small 

 number of tentacles, and the fact that the gonads are not subdivided. Tlie 

 smallest number of tentacles described from any species of the genus is fourteen, 

 in Pegantha martagon (Haecl^e], System, 1879). 



Aeginella dissonema Haeckel. 



Haeckel, 1879, Syst. der Medusen, p. 340, taf. 20, fig. 16. 



We took one specimen of this Medusa in South Malosmadulu atoll, January 

 15, surface. Drawings made from life agree perfectly with the figures given 

 by Haeckel (System, taf. 20), and by Mayer (Bull. Mus. Corap. Zool., vol. 

 37, plate 14, fig. 30), except that our specimen was altogether colorless, instead 

 of having green pigment spots on the stomach. The only other described 

 species, Aeginella bitentaculata Quoy et Gaimard, seems to differ very slightly 

 from Aeginella dissonema Haeckel. 



II. SCYPHOMEDUSAE. 



Aurelia maldivensis, sp. nov. 



Plates 6 and 8, Figs. 33, 33, 37. 



This Medusa is by far the most aberrant species of Aurelia, to which genus 

 I rather doubtfully refer it. The bell is disc-shaped, of very solid consistency, 

 and rather thick ; it is about two hundred and fifty mm. in diameter, and 

 slightly more than one third as high as broad. Its outline is broken by eight 

 deep indentations, forming eight marginal lappets, each of which bears a slight 

 central depression at its margin. At the base of each of the eight indentations 

 lies a prominent sense organ (Plate 6, Fig. 23). In their proportions these 

 sense organs differ considerably from those of Aurelia flavidula Per. et Less., 

 although they agree with them in general structure. They differ, however, 

 in their connection with the stomach, which here consists of a single straight 

 radial canal, which instead of opening into a broad circular cavity, connecting 

 on either side of the sense organ with the ring canal, spreads but slighth', 

 forming only a small cavity, which sends out two narrow branches, one on 

 either side of the sense organ, to the ring canal. No other chymiferous 

 vessels open into this enlarged cavity, except that it usually anastomoses with 

 the neighboring radial canal on either side. This condition is, however, not 

 con.stant. There are three short canals which arise from under the floor of 

 the expanded cavity. One of these is broad, short, and runs to the otocyst ; 

 the other two form a horseshoe, embracing the otocyst, antl run into the two 



