376 



p. HERBERT CARPENTER. 



There is one Crinoid, however, in which no stem is ever 

 developed, but the elements of the apical system retain their 



Tig, IX.— Pentacrinoid larva of Antedon rosacea. (After Wyville Thomson.) 

 1. Terminal plate at the base of the stem. 3, Basal plates. 4. 

 Radial plates. or. Oral plates. 



embryonic relations throughout life. In the remarkable 

 genus Holopus the basals and the radials are fused together to 

 form the walls of a tubular chamber, which has an irregu- 

 larly expanded calcareous base supported by tlie foreign 

 body to which the animal is attached. Wyville Thomson^ 

 has pointed out the resemblance of this mode of attachment 

 to that which prevails in the pedunculate Apiocrinida and 

 Cyathocrinidd;, but expressly states that in Holopus there is 

 ' ' Proceedings R.S.E.,' vol. ix, loo. cit., pp. 407—409. 



