i66 AN INTRODUCTION TO ZOOLOGY. 



without a velum. Jelly-fisli of this order may be dis- 

 tinguished from other types by the features of the 

 margin, which is divided into lobes, in the interstices 

 of which the marginal sense-organs lie protected: 



rig. 39.— The Girdle of Venus, Ccstum ucneris. 



hence the order has also received the name of the 

 Steganopldhalmata (medusae with covered eyes). 



The Gtencrphora are sometimes made into au order 

 of the Hydrozoa, and sometimes made into a separate 



