154 THE OCEAN WORLD. 
dages attached to the under surface of the Velella. The form of the 
individuals is much more varied, inasmuch as they are extremely 
contractile. Nevertheless, they have considerable resemblance to 
the corolla of a hyacinth. 
These reproductive individuals are at the same time nurses. 
The Meduse originating by budding in the case of these reproduc- 
tive individuals, constitute the sexual state of the Velelle. They 
exist, in short, in two alternate states: the one sexual, producing 
eggs ; in this state they are isolated individuals of the Meduside, 
which never group themselves or form colonies ; the other aggregate 
state is non-sexual, and in it they form swimming colonies, under the 
special designation of Véele//a. 
The genus Velella, so called by Lamarck, is found widely diffused 
in the seas of Europe, Asia, America, and Australia. One species, 
V. spirans, is often taken on the southern coasts of England and 
Ireland. The animals are also met with far out at sea, and often 
collected together in considerable masses, old and young together. 
Such is a brief account of the strange facts to which the careful 
study of these lower animals initiates us. 
In the genus ataria the body is oval or circular, sustained by a 
compressed sub-cartilaginous framework, much elevated, having a 
muscular, movable, longitudinal crest below, and provided in the 
middle with a free proboscidiform stomach and a single row of 
marginal tentacular suckers. De Blainville was inclined to consider 
the very small animals which Eschscholtz termed Ratarie as young 
and undeveloped Veledla. M. Vogt sets the matter at rest that the 
Rataria are the young of Velella, which have acquired, by little and 
little, the elliptical form, but that the limb is only furnished at a later 
period to the reproductive individuals. These Ratarise are engen- 
dered, according to Vogt, by the naked-eyed Medusz born of the 
Velella, and owe their existence to the eggs produced by these 
Medusze. 
The second genus Forpita consists of colonies of floating animals 
furnished with a cartilaginous, horizontal, and rounded skeleton, but 
they are destitute of crest or veil. The body is circular and de- 
pressed, slightly convex above, with an internal circular cartilaginous 
support, having the surface marked by concentric striz crossing other 
radiating strize, the upper surface being covered by a delicate mem- 
brane only. The body is concave below; the under surface is 
furnished with a great number of tentacles, the exterior ones being 
