180 



ZOOLOGY 



In Pericolpa four of the pedal lobes, inter-radial in position, bear 

 tentaculocysts (tc.) ; four others, per-radially situated, give origin to long, 

 hollow tentacles (t.). In the more complex genera there are eight additional 

 adradial tentacles. 



The mouth (mth.) is very large, and leads by a wide manubrium (mnb.) into 

 a spacious stomach (st.), which is continued quite to the apex of the cone. In 

 the wall of the stomach are four wide per-radial slits, leading into an immense 

 circular sinus [tire. ».). As in Lucernaria, there are four wide inter-radial im- 

 fimdibula. The gastric filaments (g. y.) are very numerous, and the elongated 

 U-shaped gonads (gon.) are eight in number and adradial. 



The coronary groove is characteristic of the group : but in other points — 

 such as the number of pedal and marginal lobes, tentaculocysts, and tentacles 



fO^ 



Fig. 13?.— Nausithoe. The entire animal from the oral aspect, ar. adradii ; g. gonads ; g.f. 

 gastric filaments ; ir. inter-radii ; m. circular muscle of sub-umbrella ; pr. per-radii ; rt. tenta- 

 culocysts ; sr. sub-radii ; t. tentacles. The black cross in the centre represents the mouth. 

 (From Lang's Comparative Anatomy.) 



— there is great variation. Pericolpa and its allies (Peromedusce) resemble the 

 Lucemarida and the members of the order Cubomediisoi in the presence of 

 tamioles and inter-radial septa : Ej>hyropsis and its allies (Cannostomce) 

 resemble the order Discophora in the absence of these structures. The scyphula 

 larva of Nausithoe (Fig. 133) lives as a parasite in the interior of a horny 

 sponge. 



Order 3. — Cubomedus^e. 



The Jelly-fishes forming this order are, as the name implies, of a more or less 

 cubical form, resembling a deep bell with somewhat flattened top and square 

 transverse section. They resemble the hydrozoan Medusa? more than any of the 

 other Scyphozoa. The best known species, Charybdcea marsupialis (Fig. 134), is 

 about 5 cm. in diameter and of very firm consistency. 



