186 • PERCY SLADEN TRUST EXPEDITION 



LEPTOMEDUSiE. 



1 7 . L AODICE ?. 



Locality. Amirante Isles, Surface. 9 Oct. 1905, gg. 1 specimen. 



This specimen is probably a young Laodice, but the absence of gonads, which have 

 not yet begun to develop, makes the determination of the genus uncertain. The umbrella 

 is saucer-shaped, about 4 mm. in diameter, and moderately thick. The tentacles, not 

 exceeding sixty in number, are very slender and short, with small basal bulbs partly 

 extending over the margin of the umbrella and without a well-defined spur. There are 

 a few marginal bulbs, from some of which tentacles have been broken off. Between every 

 two tentacles-or bulbs there is generally a single cordylus. Cirri are also present, but not 

 many remain. A conspicuous black globular ocellus is situated on the inner side of most 

 of the basal bulbs of the tentacles ■ and marginal bulbs. 



18. TiAEOPSis ROSEA, Agassiz and Mayer, 1899. 



Tiaropsis rosea, Maas, 1905, p. 30, Taf. 7, figs. 45 — 47. 

 Tiaropsis rosea, Mayer, 1910, p. 260. 



Locality. Mauritius. 125 — fms. 22 Aug. 1905, a. 1 specimen. 



Description of the specimen : — Umbrella, about 3 mm. in diameter, moderately thick, 

 and hemispherical. Velum broad. Stomach cross-shaped. Four radial canals. Gonads 

 upon the radial canals, forming globular sacs near the stomach. Four large perradial 

 tentacles, with pigmented basal bulbs. Seven marginal bulbs between every two tentacles. 

 Eight adradial sensory vesicles, with a large black roundish ocellus, situated at the base 

 of the vesicle and on the inner side. 



This specimen, though much smaller in size, agrees very closely with a Tiaropsis 

 described by Maas from Damar, Malay Archipelago. Maas' description and figures are 

 based upon a single adult specimen about 15 mm. in diameter, and he considers it to be 

 the adult stage of Tiaropsis rosea of Agassiz and Mayer. It has yet to be definitely 

 proved that Tiaropsis rosea of Agassiz and Mayer found in Suva Harbour, Fiji, is an 

 early stage of Tiaropsis rosea, Maas. 



The arrangement of the marginal bulbs may help to determine this species. There 

 are seven in each quadrant, situated as follows : — three in the interradial portion, and 

 two on the perradial side of the two sense organs. The gonads do not extend along the 

 radial canals as figured by Maas, but the specimen has the appearance of being immature 

 and has probably not reached its maximum growth. 



Phialidium sp. ? 



There are apparently two species of Phialidium in the collection, but the specimens 

 are not in a condition suitable for the determination of species. 



19. Phialidium sp. A. 



Locality. North of Chagos, Lat; 4° 16' S., Long. 71° 53' E., Surface (Temp. 86° F.). 

 17 May, 1905, B. 5 specimens. 



Umbrella hemispherical, 3 — 5 mm. in diametei". Stomach quadrangular, on a slight 



