REPORT ON THE DEEP-SEA MEDUSAE. 



lxxxv 



modifications of it are present in both sections, which make it possible to confound the 

 formations derived from them. The Narcomedusse, especially, approach the Acraspedee 

 strikingly, the Cubomedusse the Craspedotse. In spite of this, the two groups are 

 genetically entirely different, and it is therefore quite to the purpose to consider the 

 two principal forms of the coronal intestine separately ; we designate the former, the 

 vascular corona, the latter the pouch corona. 



§. 122. Vascular corona of the Craspedotse (" corona canalium "). In the majority 

 of the Craspedotse one and the same form of the coronal intestine is maintained, the 

 vascular corona, which must be regarded as the typical and original form for this section. 



Fig. M. Eucopc campanulata (Leptomeduste, Eucopidaj). 



Subumbral aspect, [a) Quadrate oral opening, (s) Ovaries, (qj) Perradial canals. («•) Coronal canals 

 (v) Velum, (ov) Velar marginal vesicels, (adradial). (h) Umbrella cavity, (re) nerve ring, (oc) 

 Ocelli at the swollen bases of the tentacles, (ug) Gelatinous substance of the umbrella. {() Tentacles. 



It is composed of four narrow, perradial canals (fig. M cp) which run out from the four 

 angles of the central stomach, and pass through the subumbrella to the umbrella margin, 

 where they are united by a coronal canal (cc) (comp. Pis. I. II.) The typical quadrUocula r 

 vascular corona of their Hydropolyps has arisen from the simple gastral space of their 

 predecessors the Hydropolyps, by their two walls (calyx wall and peristom wall) being 

 laid together and fused in such a way that only four narrow radial canals remain open 

 between them. The broad concrescentic surfaces between the four perradial canals still 

 contain in the developed Craspedotse the important (originally double) layer of 



