734 EDWARD T. BROWNE. 



open ; its margin furnislied with a large number of long narrow lips, which are strengthened 

 by an external rib. Radial canals about 100 — 150 in number, very short. Gonads upon all 

 the radial canals, extending nearly from the stomach to within a short distance of the circular 

 canal. Tentacles about 10 — 15, with basal bulbs having a long lateral extension along the 

 margin of the umbrella. Numerous marginal bulbs, closely packed together, about two to 

 three between every two radial canals. Marginal sense organs very numerous, about two to 

 four between everj' two marginal bulbs. 



Size. Umbrella about 60 mm. in length and about 30 mm. in height. 



Distribution. Indian Ocean, Maldive Is., Haddumati and Goifurfehendu (Gardiner). 



The collection contains four specimens : 



A. Umbrella 45 mm. in width and 20 mm. in height. Stomach 26 mm. in diameter. 

 Radial canals about 120. Tentacles, 10. Marginal bulbs about 12 between every two tentacles. 



B. Umbrella about 60 mm. in width and 25 mm. in height. Radial canals about 100. 

 Tentacles 10, perhaps more. This specimen is in bad condition; the margin of the umbrella 

 damaged and the mouth torn away. 



C. Umbrella about 60 mm. in width and 30 mm. in height. Radial canals estimated 

 at 150. Tentacles 15. The specimen is in bad condition. 



D. Umbrella about 60 mm. in width and about 20 mm. in height. Mouth 43 mm. in 

 diameter. Radial canals about 148, their length about 10 mm. Tentacles 13. 



The thickness of the umbrella (fig. 2) is so great that the sub-umbrella cavity is reduced 

 to a mere shallow depression round the margin of the umbrella. The oral lips (fig. 9) are 

 long and thin, about 3 mm. in length, without a sinuous margin. On the external side of 

 every lip there is a longitudinal rib, which extends into the wall of the stomach, and on 

 the inner side a corresponding g^roove. There are about as many oral lips as radial canals. 

 The gonads (fig. 4) are situated on both sides of every radial canal and do not hang down 

 in bands or folds. The tentacles are few in number and are not arranged at equal distances 

 apart. Their basal bulbs (figs. 6 — 8) have long lateral extensions along the margin of the 

 umbrella. The marginal bulbs (fig. 5) are very minute and have at their apex a circular 

 cluster of nematocysts. 



In my account of Aequorea norvegica (1903) I made the following statement : " The exact 

 shape of the stomach and whether the mouth is open or closed are scarcely suitable for 

 generic characters. The feet that an Aequorid is occasionally caught with its mouth open is 

 no evidence that it is permanently kept open." This statement must now be modified. It 

 referred to the genera Aequorea and Polycanna and with them it probably holds good, as 

 neither has a rudimentary stomach. All the species of the Aequoridae, which I had then 

 seen, possessed a mouth capable of closing up, but since I have seen these Maldive specimens 

 my statement about the exact shape of the stomach for a generic character becomes untenable. 



The stomach is quite rudimentary and is practically absent, as its lower wall is only 

 about 2 mm. in length, so that the mouth must always remain wide open. It appears to me 

 that the function of the stomach has been removed to the canal system. The medusa probably 

 lives upon organisms of microscopic dimensions, such as unicellular algae and protozoa, which 

 are picked up by the endoderm cells lining the canal system. The water containing these 

 organisms, alter circulating in the canal system, j^robably passes out through the numerous 



