182 PERCY SLADEN TRUST EXPEDITION 



the umbrella. Stomach large, occupying more than half the cavity of the umbrella. 

 Mouth large, and its margin in folds. Four fairly broad perradial canals, without any 

 lateral processes, and with a slit-like union with the stomach along its whole length ; 

 thus forming the so-called " mesenteries " which attach the stomach perradially to the 

 wall of the sub-umbrella. Four gonads, isolated perradially, and arranged in eight 

 adradial bands, which are composed of bifurcated transverse folds and united interradially 

 by a transverse fold. Four long perradial tentacles, with laterally compressed basal 

 bulbs clasping the margin of the umbrella. Also very minute interradial and adradial 

 tentacles, and a few marginal bulbs without tentacles. A blackish ocellus on the outer 

 side of all basal bulbs of the minute tentacles and marginal bulbs. 



Size. Umbrella about 3 "5 mm. in width and 6 mm. in height. 



The collection contains only one specimen, and it is in a splendid state of preser- 

 vation, but with the margin contracted inwards. 



This new species, which 1 have great pleasure in naming after the leader of the 

 "Sealark" expedition, has a character well-marked by the presence of four perradial 

 canal-like bands upon the ex -umbrella. These bands are probably brightly coloured 

 in the sea. They extend beyond the margin on to the outer edge of the basal bulbs 

 of the large tentacles and , contain nematoc3^sts. Although ocelli are clearly visible on 

 the basal bulbs of the minute tentacles, still they cannot be seen upon the basal bulbs 

 of the large perradial tentacles. I am inclined to take the view that this species has not 

 more than four large tentacles and that the minute tentacles remain in a rudimentary 

 condition. The gonads show ova fairly well advanced, so that the specimen is not an 

 early stage. 



12. PANDiEA juv. 



Locality. Chagos Archipelago, Salomon Atoll. 10 — fms. 1 July, 1905, P. 

 1 specimen. Surface. 5 July, 1905, Q. 2 specimens. 



The specimens are young stages in a contracted and crumpled condition. The smallest 

 is about 'I'b mm. in diameter, its umbrella has conspicuous longitudinal ridges carrying 

 nematocysts. There is a nematocyst track corresponding to every tentacle and bulb. 

 The perradial ridges extend to the summit of the umbrella and the other ridges or tracks 

 are shorter, their length and size being correlated with the age of the tentacle. The 

 development of the gonads is just commencing and their position is marked by small 

 isolated pits in the wall of the stomach. There are seven tentacles and a few adradial 

 bulbs, the latter are at different stages of growth. A conspicuous black ocellus is situated 

 on the outer side of all the basal bulbs of the tentacles and on some of the larger adradial 

 bulbs. 



The second specimen is a little older and about twice the size of the smallest specimen. 

 In this specimen the stomach has flattened out and the mouth expanded to its extreme 

 limit. The four perradial canals leave the stomach close to the four corners of the mouth. 

 There are nine tentacles and seven tentacular bulbs, each one having a black ocellus. 



The third specimen closely resembles the last one. It shows very clearly that the 

 adradial tentacles do not all begin to develop at the same time. 



