393 DISCOVERY REPORTS 



very large and conspicuous, more than three times as long as the flatly rounded ocular 

 ones, and separated from them by deep clefts. Sixteen long tentacles arise from the floor 

 of the subumbrella at a small distance from the bases of the marginal lappets. They are 

 about as long as the radius, 2 mm. broad at the base, hollow, tapering, laterally com- 

 pressed, and with a wa\7 thickening along the inner narrow edge covered with nemato- 

 cysts. Between each pair of rhopalar lappets there is, in the middle, one of these long 

 tentacles, and on each side of the same are the small velar lappets; between these 

 and the rhopalar lappets there are small stunted or pointed buds of tentacles, usually 

 one on each side. The mouth tube is simple, four-cornered, 8 mm. long. The mouth 

 arms are 6 mm. long, with free edges but little folded, and on the border provided very 

 irregularly with clusters of nematocysts (Plate XV, fig. 6). 



The central stomach is 15 mm. broad, circular in outline, with about sixty radiating 

 canals; they run from the periphery of the central stomach to the peripheral circular 

 canal, which lies at a small distance from the bell 

 margin. The rhopalar canals show the beginning only 

 of branching, but no anastomoses with the inter- 

 rhopalar canals. The latter are much narrower than 

 the former. The inter-rhopalar canals, always two or 

 three in number, lying between each pair of rhopalar 

 canals, remain simple, unbranched, and are slender 

 and run mostly straight or are rarely a little curved. 

 The ring canal is conspicuous, lying under the bases 

 of the tentacles. Extracircularly the ring canal gives 

 rise to a blind, short, pointed canal into each velar 

 lappet, and a broad rhopalar canal, which immediately p.^ ^^ Phacellophoyaornata,Ntrv\\\. 

 forks and sends a thin, curved, blindly ending portion of the border with canals, 

 branch into each rhopalar lappet, and a third thin x 5. 

 branch to the sense organ (Fig. 12). 



The gastric filaments are very long, and are arranged in four perradial, horseshoe- 

 shaped clusters of about twenty-five each. 



The colour of the disc is transparent ; uniformly whitish yellow, without any brilliant 

 colours . The tentacles , stomach , vessels and mouth arms are whitish and not transparent . 



This very young developmental stage of this relatively rare medusa was found in 

 Elephant Bay, Angola. The locality merits interest because the species has been found 

 hitherto in very few places: Eastport, Maine, and in the Bay of Fundy; one single 

 specimen is mentioned by Browne (1909) from the South Atlantic — 'Scotia', St. 98, 

 34' 2" S, 49° 7' W, 200 miles east of Montevideo, surface. 



The differences (outline of the stomach, number of tentacles, simple straight form of 

 the radial canals, which do not anastomose, and the transparent colour) between the 

 present specimen and the much larger ones described by Verrill (1869), Fewkes 

 (1888), Browne (1909) and Mayer (19 10) are surely to be attributed to the early stage of 

 development. 



