REPOKT ON THE DEEP-SEA MEDUSAE. 61 



slightly above the umbrella margin, their lobe pouches (bl) never reach an independent 

 development. The development is consequently proportion-ably greater of the four 

 radial pouches, whose length is nearly two-thirds that of the whole length of the umbrella, 

 and only partially occupied by the conspicuous genitalia, lying in their subumbral wall 

 (comp. figs. 2-7, bp). 



The genitalia (PI. XVI. figs. 2-7, s, figs. 10, 11; PI. XVII. figs. 17-19, 21). The 

 specimen examined was a mature female, and showed most distinctly that the ova in the 

 Lucernaridse (as in all Stauromedusse) are developed from the endoderm of and in the sub- 

 umbral wall of the radial pouches, then fall into their cavity, reach the central stomach 

 through the gastral openings, and are finally expelled through the mouth ; all parts of the 

 gastrovascular system of the uninjured Medusa contained when opened numerous, loose, 

 ripe ova. The ovaries (figs. 2, 3, sf) form eight broad plates occupying the greater part 

 of the subumbral wall of the four perradial gastral pouches, and are distributed in pairs in 

 such a manner that the two genitalia separated by an interradial septum, form a connected 

 pair. The two ovaries lying in one and the same radial points, therefore form two 

 different pairs (comp. my System der Medusen, 1879, p. 386). The interradial interval 

 between each two reproductive leaves is considerably smaller than the perradial interval ; 

 their distance from the distal margin of the four radial pouches is also much less than 

 from the proximal margin (comp. figs. 2, 3, sf). Their outline is semi-oval or almost 

 lanceolate, and broadened in the distal third. 



The structure of the ovaries in Lucernaria bathi/phila is very peculiar, and more 

 complicated than in all other Stauromedusse hitherto known. Even with the naked eye 

 the upper surface of the eight reproductive glands appears granular as if paved, and a 

 slight magnifying power (fig. 21, sk) shows that each genitalium is composed of a large 

 number (nearly 200-250) of entirely separate sacs. These have an irregular roundish or 

 polygonal outline, averaging 1 mm. in diameter (the smallest rather under ^ mm., the 

 largest rather above 1-^ mm.). Whilst in all other Lucernaridse hitherto known these 

 reproductive sacs (" sacculi genitalis," sk) represent simple glands with a single hollow 

 space and excretory passage, in our deep-sea species they are lobed glands composed of 

 several separate lobes or follicles, each having its own cavity and its own excretory 

 passage. Each separate sac (fig. 10, seen from the surface, fig. 18, in perpendicular longi- 

 tudinal section) is therefore usually composed of from thirty to fifty follicles (sb). Each 

 separate follicle (fig. 11 from the surface, fig. 19 in longitudinal section) contains a 

 "sinulus" (sc) or secondary cavity, which opens by a "ductulus" or secondary excretory 

 passage (si) into the "sinus genitalis," or principal cavity of the sac (fig. 18, sc) ; the last 

 opening by its ductus or principal excretory passage (si) into the radial pouch (sa). The 

 ova (fig. 19, so), which are developed from the endodermal epithelium of the follicle, 

 pass first from its sinulus (so) into its ductulus (si), thence into the sinus of the sacculus 

 (fig. 18, sc), and from the sacculus by the ductus (si) into the radial pouch. The ovary of 



