REPORT ON THE DEEP-SEA MEDUSA. 101 



separated from it by the cathammal plate of the septum (ks), they belong genetically to 

 the subumbral wall. Each reproductive leaf is really a thin fold of this suburethral wall, 

 inasmuch as the gelatinous supporting lamella of the latter forms a leaf-shaped process 

 (" sterigma," fig. 10, zs), which is covered on both sides by the subumbral endodermal 

 epithelium. The reproductive elements, which fall freely when ripe into the pouch, are 

 developed from the subumbral endodermal epithelium on both sides of the sterigma. 

 They originate from the subepithelial endoderm cells, which cover both surfaces of the 

 federal process. The latter corresponds to the sterigma or fulcral frame in the genitalia 

 of the Peroniedusse (p. 83), and formed in both female specimens before me a broad, 

 fibrous, axial plate (fig. 10, zs), thickly covered with later and earlier egg cells (so). The 

 reproductive leaves are covered on both free surfaces by the connected cylindrical 

 epithelium of the endoderm (fig. 10, pd). The ripe reproductive elements pass from 

 the radial pouches into the stomachs through the gastral openings, and are expelled 

 through the mouth. 



o 



Order VIII. DISCOMEDUSiE, Hseckel, 1866. 



Acraspeda with eight to sixteen or more sense clubs (always four perradial and four 

 interradial, besides these occasionally several accessory clubs) ; in each sense club an 

 auditory club with an endodermal otolite sac and often an eye at the same time. 

 Marginal lobes always eight pair of primary (Ephyra lobes) and frequently numerous 

 accessory (velar lobes) besides. Tentacles sometimes present, sometimes wanting. 

 Stomach surrounded by a corona of radial processes (8 to 16 to 32 or more; sometimes broad 

 radial pouches, sometimes narrow radial canals. Genitalia four interradial folded 

 swellings in the subumbral gastral wall, developed from its endoderm (rarely divided 

 into eight adradial swellings) ; sometimes invaginated in the form of a pouch towards the 

 inside in the central gastral cavity, sometimes evaginated hernia-like towards the outside 

 in the umbrella cavity. Umbrella depressed and discoid. The general fundamental form 

 of all Disconiedusse is the octomeral Ephyra. 



Fikst Sub-order of the Discomedus^:, CANNOSTOM^E, Hasckel, 1879. 



Discomedusse with undivided proboscis or oral tube, a simple, quadrangularly prismatic 

 oesophagus, without oral arms ; with simple or quadrangular central oral opening, and 

 with short, solid marginal tentacles. 



Family, Ephyeid^;, Hseckel, 1877. 

 Ephtridj:, Hreckel, System der Medusen, 1879, taf. xvii., xviii., p. 450. 

 Cannostomse with broad radial pouches, without terminal branched canals. Discome- 



