484 POLYPI. 



rated without destroying the life of either. They are gelatinous, diaphanous, 

 and move nearly in the manner of a Medusa. The receiver produces from 

 the bottom of its cavity a chaplet which traverses a semi-canal in the received, 

 and appears to be composed of ovaries, tentacula, and suckers, like those of the 

 preceding genera. 



This genus has been divided by Messrs Quoy and Gaymard according to 

 the relative form and proportions of the two individuals. 



Thus in 



DIPHYES proper, 



The two individuals are almost similar and pyramidal, with some points round 

 their aperture which is at the base of the pyramid. 



In CALPES the received is still pyramidal, but the receiver is very small and 

 square. 



In ABYLES the received is oblong or oval, and the receiver somowhat small 

 and bell-shaped. 



In CUBOIDES the received is small and bell-shaped, the receiver much 

 larger and square. 



In NAVICULA the received is bell-shaped ; the receiver is large, but has the 

 figure of a wooden shoe. 



There are several other combinations. 



CLASS IV. 

 POLYPI *. 



OUR fourth class of the Radiata or Zoophytes has been thus named 

 because the tentacula which surround their mouth give them a slight 

 resemblance to an Octopus called Polypus by the ancients. The 

 number and form of these tentacula vary. The body is always cylin- 

 drical or conical, frequently without any other viscus than its cavity, 

 and frequently also with a visible stomach, to which adhere intestines 

 or rather vessels excavated in the substance of the body like those of 

 the Medusae ; in this latter case we usually find ovaries also. Most of 

 these animals are capable of forming compound beings, by shooting 

 out new individuals, like buds. They also, however, propagate 

 by OVA. 



* This class of animals, although nearly at the end of the series, is one of the largest, 

 and certainly the most singular of the whole. Such is the enormous accumulation of the 

 stony envelopes formed by them in certain seas, that islands are produced, coasts extended, 

 and harbours blocked up by them. The late lamented M. de Lamarck has even hazarded 

 fhe idea, tht the calcareous strata of the globe may hare been produced by them. Polypi 



