386 ACALEPHA. 
It is directly after these hydrostatic Acalepha that we may 
place the 
Diruyes, Cuv. 
A very singular genus, where two different individuals are always 
found together, ‘one encased in a cavity of the other, but susceptible 
of being separated without destroying the life of either. They are 
gelatinous, diaphanous, and move nearly in the manner of a Me- 
dusa. The receiver produces from the bottom of its cavity a chaplet 
which traverses a semi-canal in the received, and appears to be com- 
posed of ovaries, tentacula, and suckers, like those of the preceding 
genera. 
This genus has been divided by Messrs Quoy and Gaymard ac- 
cording to the relative form and proportions of the two individuals. 
Thus in 
DrpuyEs, proper, 
The two individuals are almost similar and pyramidal, with some 
points round their aperture which is at the base of the pyramid(1). 
In Carres the received is still pyramidal, but the receiver is very 
small and square. 
In Axytes the received is oblong or oval, and the receiver some- 
what small and bell-shaped. 
In CunorpEs the received is small and bell-shaped, the receiver 
much larger and square. 
In Naviovuta the received is bell-shaped; the receiver is large but 
has the figure of a wooden shoe(2). | 
There are several other combinations. 
(1) Bory Saint-Vincent, Voy. aux Isles d’ Afrique. 
(2) See the Mem. of MM. Quoy and Gaym., Ann. des Sc. Nat., X. 
