POLYZOA. 95 



state the vesicles appear shortened and closed at the mouth 

 (f. 3,) but from their translucency show the included 

 animal with its arms closed together, (but neither shortened 

 nor folded as they are in Hydrae,) with ils body bent up, 

 and lying in the bottom of tlie vesicle ; when the animal 

 protrudes, the closed mouth of the vesicle rolls outwards 

 and extends, appearing to be continuous with the body of 

 the animal, the arms or tentacula shoot out and spread 

 into a funnel-like form, at the same time that the body of 

 the animal becomes erect, (f. 4,) in this state it is easy 

 to perceive the whole structure of the animal, its arms, 

 gullet, stomach, intestine, and ovarium. The arms, 

 (f. 4, a.) in this species are ten in number, half the entire 

 length of the animal, and almost linear, and although 

 incapable of any individual shortening or retraction, as in 

 Hydrse, are extremely flexile, and have a range of delicate 

 laminge along their sides and front, which are kept in con- 

 stant and rapid movement during their expanded state, 

 calculated to produce a current towards the mouth and 

 probably replacing the branchial apparatus of the Ascidiae, 

 as a somewhat analagous contrivance has been observed 

 in the Moluscous Genus Clio. The mouth is placed within 

 the circle formed by the arms, from which the gullet, (/>,) 

 extends downwards to the stomach, (c,) which occupies the 

 middle point of the vesicle, and is of a roundish figure 

 and fleshy substance ; from the lower part of the stomach 

 the intestine, (c?,) bends upwards along the front towards the 

 edge of the vesicle ; in it, scybala or rounded pellets of dark 

 encrementitious matter may generally be observed. By 

 attentive observation a muscle may be seen to act in draw- 

 ing up the animal, originating near the margin of the vesicle 

 above, and inserted into the animal beneath the stomach ; 

 no doubt, it possesses an antagonist calculated to draw the 

 animal within its cell, and originating of course, in the 

 lower part of the vesicle. From the stomach, the viscus 



