Mr. F. S. Conant on the Cabomedusse. 37 



Charyhdea is a strong and active swimmer, and presents a 

 very beautiful appearance in its movements throug'li the water. 

 The quick vigorous pulsations contrast sharply with the 

 sluggish contractions seen in most Scyphomeduste. When 

 an attempt is made to capture one it will often escape by 

 going down into deeper water — as, indeed, do other jellyfish. 

 Escape from observation is all the more easy by reason of 

 the entire absence of pigment, except for the small amount in 

 the sensory clubs. The yellowish or brownish colour usually 

 stated as common in the Cubomedusse is nowhere present in 

 C. xaymacnna. 



The environment in which Tripedalia was found is still 

 more unlike that in which Cubomedusse have been taken 

 heretofore. It was obtained in two localities, both of which 

 were cut off from the main body of the harbour, and so from 

 the ocean, by peninsulas and islands covered with a growth 

 of mangrove. The water was shallow and discoloured with 

 organic matter, and the bottom for the most part a black mud. 

 The regions were virtually mangrove-swamps. It was under 

 the shelter of the overhanging mangrove boughs, among their 

 half-submerged roots, that the Tripedalia was found thriving 

 in large numbers. Conditions more strikingly unlike those 

 of the pure deep sea could hardly be imagined. 



T. cystophora is as quick and vigorous a swimmer as the 

 species of Charyhdea. In one case as many as 110 pulsations 

 were counted in a minute. Its brownish-yellow colour 

 enables it to escape observation not infrequently in the dis- 

 coloured water. 



C. — Anatomy. 



An abundance of material of both species was preserved in 

 several ways and has furnished subject-matter during the past 

 year for investigation of the adult anatomy of the Cubo- 

 medusge. The results have been embodied in a paper whose 

 publication I hope will not be greatly deferred. Meanwhile 

 the mention of one or two points may not be out of place. 



The parts to which especial attention was given were the 

 vascular lamellge, or cathammal plates, and the nervous 

 system. The vascular lamellse, being definite areas where 

 the two walls of the gastro-vascular system hava come 

 together and fused, are interesting because they show how 

 the present structure of the gastro-vascular system of the 

 Cubomeclusse has come about from a simpler undivided con- 

 dition. It was hoped that their study might throw definite 

 light on the affinities of the group. The results, however, 

 were unsatisfactory, for while one part of the system of 



