BROWNE— MEDUSJE' FROM THE INDIAN OCEAN 185 



the substance of the umbrella. Between every two tentacles are isolated clusters of 

 nematocysts, which extend over the ex-umbrella from the margin up to the summit, and 

 these clusters are similar to those described in the other species of the genus. Though 

 the specimen is in fairly good condition, it is not suitable, owing to contraction, for the 

 making of a good drawing. 



15. Peoboscidactyla sp. ' 



Locality. Farquhar Group, Providence Is., Surface. 3 Oct. 1905, x. 1 specimen. 



Umbrella about 1'25 mm. in diameter. Five main radial canals, each with a lateral 

 branch. Ten tentacles. No medusa-beds. 



The specimen is not in very good condition. The number of radial canals shows that 

 it is abnormal, and as each canal has only one branch it is evidently a young stage. 



16. Anthomedusa, Genus?. 



Locality. Mauritius. 300 — fms. 22 Aug. 1905, C. 1 specimen. 



The umbrella is in a contracted condition, about 5 mm. in width and probably when 

 alive about the same in height, rather thick. It has on its exterior surface four conspicuous, 

 prominently projecting, perradial ridges, which extend from the margin to, or nearly to, the 

 top of the umbrella. These ridges have rather a blunt rounded edge, with what appears 

 to be a narrow shallow groove running along the middle of the edge. From the shape and 

 general appearance I do not think that these ridges were formed artificially either by 

 preservation or by contraction, but existed in the living specimen. I am not so sure, 

 however, about the groove along the middle of the ridge, it might be due to shrinkage. 

 I cannot recall seeing a figure of any Anthomedusa with ridges, such as appear in this 

 specimen. The velum is very narrow, and the sub-umbrella is well covered with a layer 

 of fine muscles. The stomach is rather contracted, and has a plain circular mouth. In its 

 contracted condition it is rather broad, and sac-shaped. It is not likely to extend beyond 

 the margin of the umbrella even when fully stretched out. There are four conspicuous 

 radial canals. The wall of the stomach has the appearance of being covered with male 

 gonads, and if so, then the gonads are at an early stage as there is no definite swelling. 



The medusa has only two opposite perradial tentacles, both of which are unfortunately 

 broken off at the basal bulbs and leaving not the slightest clue as to their structure. The 

 basal bulbs are rather large a,nd globular, and are attached to the margin of the umbrella, 

 but do not project into the substance of the umbrella. The other two opposite perradii 

 are naturally without any tentacles and also without any rudimentary bulbs, and the 

 whole margin is also without minute rudimentary bulbs. There is apparently a patch of 

 nematocysts on the margin of the umbrella in each of the four perradii, and there is also 

 evidence of a short extension of them along the ridges of the ex-umbrella. No ocelli could 

 be found. 



With the complete loss of the tentacles it is impossible to determine the genus. It 

 has certainly only two opposite tentacles, so it may be a Dicodonium, a Zanclea, or even 

 a new genus. 



SECOND SERIES— ZOOLOGY, VOL. XVII. 24 



