416 ACALEPHA. PHYSALIA. 



Gen. 20. PHYSALIA, Lam. Holothuria, Lin. 



Body free, gelatinous, membranous, irregular, oval, slightly com- 

 pressed on the sides, vesicular interiorly, with a crest on the 

 back, and tentacula under the belly ; tentacula numerous, 

 unequal, of various kinds ; some filiform and very long, others 

 short and thick ; mouth inferior, subcentral. 



The animals of this and the following genera are distinguished by one or many 

 vessels generally filled with air, by means of which they are suspended in the wa- 

 ter. These appendages are numerous and varied in their forms, and some Cuvier 

 conceives may serve for suckers, others may be ovaries, and some, longer than the 

 others, may be tentacula. Their mouth is not perceptible. 



P. pelagica, Lam. Oval, subtrigonal, with the dorsal crest promi- 

 nent, and reddish. Inhabits Atlantic ocean Lam. ii. 480. 



Gen. 21. PHYSSOPHORA, Peron. 



Body free, gelatinous, vertical, terminated above by an air-ves- 

 el ; lateral lobes distichous, subtrilobed, vesicular ; base of 

 the body truncated, perforated, surrounded by appendages 

 either conical, dilated into lobes, or subdivided and foliated ; 

 tentacular fialments more or less long. 



P. hydrostatica, Lam. Oval ; lateral vesicles three-lobed ; four of 

 the larger tentacula red. Inhabits Mediterranean sea. Lam. 

 ii. 476. 



Gen. 22. RHIZOPHYZA, Peron. 



Body free, transparent, vertical, elongated, terminated above by 

 an air-vessel ; and along the stem tentacula, of which some are 

 conical and the others filiform. 



R. ffliformis, Lam. Body filiform ; lateral lobes oblong, pendulous ; 

 the animal having the power of contracting itself into a subglo- 

 bular form. Inhabits the Mediterranean sea Lam. ii. 478. 



Gen. 23. STEPHANOMIA, Peron. 



Animal gelatinous, very long, in the form of a leafy garland fur- 

 nished with long filaments, mixed with lateral appendages. 



S. amphitritis, Peron. Body echinated, with acute foliaceous appen- 

 dages ; tentacula rose-coloured. Atlantic ocean. Lam. ii. 462. 

 This animal is said to present the appearance of a garland of azure crystal floating 



on the surface of the waves. It raises successively its diaphanous leaflets, resembling 



the leaves of ivy, with its tentacula extended for prey. 



