ANGULAR SEA-CUCUMBER. 



215 



and globose, the other small, and small broadly triangular 

 plates composing the dental apparatus. 



It is extremely variable in colour ; generally of a deep 

 purple, sometimes altogether white, sometimes purplish 

 white. The tentaeula and head of both varieties vary 

 equally, either purple or white. It varies also in the 

 pinnation of the tentaeula, and in their relative size and 

 number. The Holothuria Montagui of Dr. Fleming, founded 

 on a white variety described by Montagu, has eight full 

 sized tentaeula and two small ones, which are alternately 

 in motion, covering the mouth. The tentaeula of this form 

 are not so pinnate as in the common or purple state. The 

 Holothuria Dicquemarii of Cuvier seems to be a quadran- 

 gular variety with similar tentaeula. It varies also with 

 six angles. It can change its form at pleasure, and some- 

 times contracts itself so as to become exceedingly hard. 

 Gaertner well remarks that " in its contracted state it has 

 more of the appearance of a caterpillar than of a polype." 1- ' 



That author, who first observed it on the coast of Bri- 

 tain, gives the following characteristic description of its 

 suckers and tentaeula : — " The surface of its cylindrical 

 body is marked with six double rows of perforated knots, 

 which the animal can transform into as many legs if occa- 

 sion requires, by extending each tuberculum into a small 

 transparent cylinder, whose extremity, like that of the 

 suckers of the Starfish, sticks fast to everything which the 

 animal gets hold of, and consequently serves as an instru- 

 ment, not only to fix its body with, but also to push it 

 forward by the help of many of these suckers that are 

 formed of the several knots of different roAvs. The feelers 

 are eight or ten in number, and of the same substance and 

 colour with the head ; they are divided into several 

 branches, to which as well as to the principal stems many 



