EYED CRIDELLA. 



105 



Crlhella oculata. They were published in Wiegmann's 

 Archives for 1837, and an account of them is given in the 

 new edition of Lamarck. According to M. Sars, the little 

 Starfishes immediately after birth have the body depressed 

 and rounded, and furnished with four very short club- 

 shaped appendages, or arms, at their anterior extremity. 

 When they are a little more developed, one can distinguish 

 some papillae disposed in five radiating series on the upper 

 surface. These young Starfishes move slowly, but uni- 

 formly in a straight line, with their four arms in advance. 

 Their movement is probably effected by vibratile cilia. 

 Their arms serve also to fix them to or enable them to 

 creep slowly along the sides of rocks. At the end of 

 twelve days, the five rays of the body, which till then were 

 rounded, begin to grow ; and after eight days more, the 

 two ranges of feet, or tentacula, are developed under each 

 ray, and can assist the movements of the animal by elon- 

 gating and contracting themselves alternately, and by 

 performing the function of suckers. By that time the 

 swimming movements have altogether ceased. At last, 

 in the space of a month, the four original arms have alto- 

 o-ether disappeared ; and the animal, at first symmetrical 

 or binary, has become radiate. 





