BROWNE— MEDUS.E FROM THE INDIAN OCEAN 177 



situated, having the appearance of ova. Tv^^o large opposite perradial basal bulbs, 

 globular in shape, from which tentacles have been broken off. In each of the other two 

 opposite perradii there is a minute rudimentary bulb. There are four perradial tracks of 

 nematocysts upon the ex-umbrella, about 0"5 mm. in length. The tracks lead to an oval 

 patch of nematocysts, situated upon a slight prominence of the ex-umbrella. 



This specimen probably belongs to the genus Zanclea, as it has tracks of nematocysts 

 upon the ex-umbrella, and only two tentacles. 



6. Zanclea ?. 



Locality. Lat. 8° 16' S., Long. 51° 26' E. (between Providence and Alphonse). 

 900—0 fms. 6 Oct. 1905, aa. 1 specimen. 



The umbrella is thick, with a rounded summit, about 2 "5 mm. in height and slightly 

 less in width. The stomach at its base is cross-shaped and tapers down to a slender tube 

 terminating with a circular mouth, which is about on a level with the margin of the 

 umbrella. Upon the upper half of the stomach are situated four gonads, which occupy 

 the whole of the spaces between the four perradii. There are four perradial basal bulbs 

 all about the same size, from which tentacles have apparently been broken off Upon the 

 margin of the ex-umbrella there are four perradial tracks of nematocysts, one above each 

 of the basal bulbs. They have the appearance of straight, narrow canals, less than 0"5 mm. 

 in length. 



■ Owing to the absence of tentacles it is impossible to be sure of the correct 

 determination of the genus. It is probably a Zanclea with four tentacles. 



Genus Cyt^is, Eschscholtz, 1829. 



There have been several species of Cytceis described at intervals, and located in 

 different regions of the world. Vanhoffen, who has examined a very large number of 

 Cytceis collected by different expeditions in the Atlantic, Indian and Pacific Oceans, 

 definitely comes to a conclusion that there is only one species in this genus, and to it 

 he assigns the oldest specific name, Cytceis tetrastyla, Eschscholtz. 



There is, however, a feeling of doubt in my mind as to there being only one species 



of Cytms. I am inclined to regard Cytceis vulgaris, Agassiz and Mayer, from the Fiji 



Isles as a distinct species, and also Cytceis pusilla, Gegenbaur, from the Mediterranean. 



I think that as Vanhoffen has taken as a type the somewhat vaguely defined and badly 



drawn Cytceis tetrastyla of Eschscholtz, it will be best to follow him by grouping under 



its name at all events the following : — 



Cytceis nigritina, Haeckel, 1879, p. 74, Taf. 6, figs. 2 — 5. 



Cytceis macrogaster, Haeckel, 1879, p. 74, Taf. 6, fig. 1. 



Cytais nigritina, Maas, P904, p. 8, pi. 1, fig. 3. 



Cytceis herdmani, Browne, 1905, p. 135, pi. 1, fig. 1. 



Cytceis vulgaris, Bigelow, 1909, p. 190, pi. 6, fig. 3, pi. 40, fig. 2 and fig. 5, pi. 43, figs. 4—5. 



Cytceis tetrastyla, Vanhofien, 1911, p. 204, Text-fig. 6. 



Cytceis tetrastyla, VanhoflFen, 1912, p. 8, Taf. 1, fig. 6. 



The above-mentioned figures show specimens with large triangular basal bulbs 



extending some way up the umbrella, and the tentacles should have a pigmented 



endoderm. 



SECOND SERIES— ZOOLOGY, VOL. XVIL ' 23 



