RE-CLASSIFICATION OF MULLERIA AND HOLOTHURIA. 165 



have described, and in many cases it is absolutely impossible to 

 distinguish a true pedicel from a papilla, except in a hving 

 specimen. Many so-called pedicels have the appearance 

 of a true pedicel, but they are not used by the animal as 

 anchoring or locomotory organs. The distinction is easily 

 seen in the hving form, and I do not remember havmg seen a 

 hving Holothurian in which the dorsal appendages to any 

 great extent had the power of attaching themselves to a 

 foreign surface. The sub-genus Bohadschia is said by many 

 authors to have true pedicels all over the body. After examin- 

 ing a hving specimen of Bohadschia vitiensis I said: "The 

 pedicels are irregularly scattered, and the sucking discs are 

 apparently not well developed, since the animal does not appear 

 to use them much."* 



In many forms true pedicels are present on the trivium, and 

 the bivium is covered with papillae which may have a cyhndri- 

 cal shape and a well-developed sucking disc, or may be conical 

 and may be devoid of sucking discs. In many cases true 

 pedicels may be scattered among the dorsal papillae. 



Again, some species have no true pedicels, and these forms 

 are more highly specialized than those which have pedicels 

 on the trivium. 



The absence or presence of pedicels appears a reliable 

 means of separating the two sub -genera Halodeima and Thy- 

 miosicya. 



Nattjre of the Spictjles. 



The spicules in the genus may consist in' the simplest forms 

 of dichotomously branched " rosettes." It is easy to conceive 

 how these maj' give rise first to perforated plates and later to 

 " buttons " and " tables." Those forms possessing tables and 

 buttons may be regarded as more highly specialized than 

 those in which the spicules are in the form of " dichotomous 

 rods " and " rosettes." 



SpoUa Zeylanica, Vol. IX., Part XXXIV., p. 69. 



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