526 DESCRIPTION OF THE MUSEUM. 



sent a striking phenomenon in the rapid repro- 

 duction of such parts as they have lost. In very 

 hot weather two or three days suffice for com- 

 pleting the process ; and what is much more ex- 

 traordinary, if one of the rays is severed from 

 the body, it soon after becomes a star-fish similar 

 to the one from which it was separated. By 

 considering the form and the disposition of the 

 rays, the characters of the four genera which 

 compose this family have been determined : these 

 are the comatula, euryale, ophiura, and asterias. 

 The comatulce are contained in six cases ; we have 

 seven species, four of which were brought from 

 the South seas by Peron and Lesueur. The c. So- 

 laris is the largest, and measures 12 inches in 

 diameter. From one specimen of the c. rotularis 

 we may see the attitude which these animals 

 adopt in order to seize their prey ; suspending 

 themselves to the fuci or madrepores by means 

 of their dorsal rays, and extending the others, they 

 catch the small crabs which happen to swim 

 within their reach. Various species of eurjale, 

 vulgarly called medusas' heads, occupy the four 

 next cases ; they are remarkable for the great 

 number of divisions in their principal rays: we 

 have four species of them. The rays of the 

 ophiurce are sometimes smooth and sometimes 

 rough ; there are seven species and a great num- 



