190 PERCY SLADEN TRUST EXPEDITION 



The oral lips are similar in shape and structure as those figured for j^quorea maldivensis, 

 but are more numerous. I am not sure that it would be advisable to take the number 

 into consideration for one of the specific characters. Maas found the oral lips to be less 

 than half as numerous as the radial canals. Bigelow does not mention them in his text, 

 but a figure indicates fewer lips than canals. One of the " Sealark " specimens has about 

 the same number of lips as radial canals. 



All the specimens from the Saya de Malha Banks are in bad condition, and it is only 

 just possible to determine the species in one specimen which has a few tentacles left. 

 Their stomachs measured from 23 — 34 mm. in diameter, and radial canals numbered 

 72 to 100. 



A few notes can be given on the specimens from the other stations. 



A. The umbrella measures 42 mm. in diameter and is moderately thick. The 

 stomach measured 27 mm. and the mouth 23 mm. in diameter. Even allowing for the 

 lower wall of the stomach being considerably contracted, I doubt very much if it could 

 expand sufiiciently so as to allow the mouth to close up. There are 92 radial canals, 

 a few have developed much later than the rest and bear no gonads. Seventeen large 

 tentacles and seven much smaller in size at different stages of development. There are 

 between every two tentacles 5 — 10 marginal bulbs with excretory pores. This specimen 

 shows in a marked manner the radial muscle bands extending from the proximal end of 

 the radial canals, across the lower wall of the stomach, to the oral lips. There is a muscle 

 band in connection with every radial canal. 



B. The umbrella is shaped like a biconvex lens and measures 45 mm. in diameter. 

 The stomach is about 30 mm. and the mouth about 20 mm. in diameter. Around the 

 margin of the mouth are numerous lips, about as many radial canals, and of the latter 

 there are seventy-nine. The gonads show ova and extend as laminar bands along nearly 

 the whole length of the canals. There are 16 large tentacles and four smaller in size. 

 Between every two tentacles are situated 8 to 10 marginal bulbs, the central one is 

 usually larger than the other and shows signs of developing a tentacle. The sense organs 

 are very numerous, usually 2 to 5 between every two bulbs. 



The excretory pores in both these specimens are very conspicuous on the inner side 

 of the circular canal. They stand out like papillje. There is one corresponding to and 

 opposite every tentacle and large marginal bulb. 



Distribution. Indian Ocean and Tropical Pacific. 



25. Leptomedusa, No. 1. 



Localities. North of Chagos. 75 — fms. 16 May, 1905, A. 1 specimen. Far- 

 quhar Group, Providence Is., Surface. 5 Oct. 1905, y. 1 specimen. 



The specimens are young stages, without gonads, and they probably have not yet 

 developed their generic characters. At all events, I cannot assign them to a definite 

 genus. Mayer (1910) gives figures (PL 25, fig. 8, and PL 27, fig- 1) of early stages of 

 a Dipleurosoma which somewhat resembles these specimens. 



Description : — The umbrella is thick, not quite so high as broad, about 4 mm. in 

 diameter, without any apical projection. Velum narrow. The stomach is cross-shaped 



