REPORT ON THE ASTEROIDEA. XXL 
believe, would not meet with general acceptance on other grounds, as the Asteroidea are by 
many considered to represent a more archaic type than the Kchinoidea. 
(3.) As to whether the pedicellariz furnish characters by which the four “orders” 
indicated by Perrier may be distinguished, I consider that they are insufficient and 
unsatisfactory ; and I would venture to say that in my opinion two of the orders in 
question would be more correctly described as defined by the character of their spinulation. 
I refer to the Spinulose and the Paxillosee. In his diagnosis of the order Spinulose 
(Echinulatee), Perrier distinctly states that the pedicellarize are simply formed of modified 
spinelets (op. cit., p. 206), and in that of the order Paxillosee (op. cit., p. 249) no mention 
whatever is made of pedicellariz ; in the abridged synopsis of the orders, however, given 
above, the Paxillosee are defined as characterised by pedicellarize, formed of an ossicle of the 
skeleton and the spinelets which cover it (op. cit., p. 154). The statements in the case of 
ce 
these two “orders” would seem to negative Perrier’s argument that pedicellariz are not 
modified spinelets and that they have nothing to do with those appendages. Furthermore, 
I fail to see that the characters invoked from the modifications in the form of the pedi- 
cellarize are of sufficient importance to indicate differences of an ordinal degree. 
Apart from the above considerations, which negative the view that the pedicellarize in 
the Asteroidea afford characters by which orders may be distinguished, I make bold to 
say that | am unable to regard either pedicellarize, or spines, or any other mere tegu- 
mentary appendages as furnishing characters of sufficient importance to warrant their 
employment as taxonomic factors of ordinal rank. Though I admit that pedicellarize do 
possess characters of a certain taxonomic value, I cannot regard them as characters either 
of primary or even of secondary importance in the great question of the division of a class. 
I may remark in passing that I do not consider the plate to which Viguier has unfor- 
tunately given the inappropriate name of “ odontophore” to merit the importance which 
he has placed upon it. The plate in question, which is the basal plate of the interbrachial 
system, is pushed by development upon the first pair of adambulacral plates, or mouth- 
plates, and is moulded into form to a certain extent by these plates, its shape being largely 
dependent on the number of the rays and the character of the adambulacral plates. So 
far, however, as my own observations go, | am inclined to think that in not a few cases 
greater differences may be found to exist between the ‘odontophores,” or, as I should 
prefer to call them, “basal interbrachials,” of congeneric species, than between those of 
species of distinctly separate genera. The form of the plate appears to be extremely 
variable, and not to present characters of very great taxonomic value. 
Ill. A Classification of the Asteroidea based on Factors of Morphological Importance. 
Passing in review the various morphological features or fundamental points of struc- 
ture which are common to the whole class, the following appear to me to present char- 
