164 THE SCYPH0MEDUS.E OF THE SOUTHERN HEMISPHERE, 



SCYPHOMEDUS^E. Ray Lankaster, 1877. 



The Scyphomedusse are Medusae with Gastral filaments or 

 Phacells, with entodermal Gonads, without Velum, with marginal 

 laps of the Umbrella, without a double centralized nerve-ring. 

 Developed'originally from a Scyphostoma by Strobilation. Onto- 

 genesis, mostly change of generations often connected with a 

 metamorphosis. The sexual generation is produced by terminal 

 budding of (1) the non-sexual Scyphostoma generation. 



I. Ordo Stauromedus^e. Haeckel, 1879. 



Scyphomedusaa without organs of sense, 4 pair of adradial or 4 

 simple interradial Gonads in the sub-umbral wall. Stomach with 

 four large perradial pouches 2). 



1. Family. Tesseridce. Haeckel, 1879. 



Stauromedusa? with simple undivided margin of the umbrella, 

 without hollow margin laps. Eight simple per-and inter-radial 

 tentacles. Ring-shaped muscle on margin of Umbrella continuous. 

 In middle of Exumbrella a protuberance or stalk. 



1. Gen. Tessera. Haeckel, 1879. 



Tesseridce without stalk, with eight simple tentacles without 

 nettle knot. 



1. sp. Tessera princeps. Haeckel, 1879. 



Haeckel System der Medusen. Seite, 374. 



Tafel, XXI. Figuren, 1-6. 



Umbi-ella bell shaped, higher than broad, with conical protu- 

 berance on Exumbrella containing a gastral canal. Four simple 

 gastral filaments. Mouth tube quadrangular prismatic nearly as 

 long as the height of the Umbrella. Mouth square. Four simple 

 boof shaped Gonads. The four perradial tentacles double as long 

 as the four interradial ones. 



Size : Breadth of Umbrella, 4 mm., height 5 mm. 



(1). Haeckel, Medusen. Seite, 360. 

 (2). Haeckel, Medusen. Ibeite, 364. 



