ECHINOIDEA. II. 



2 7 



not be found in the fossil forms is of primary importance, we must admit that the fossil forms are in 

 some respect insufficiently preserved for identification. I quite agree with Professor Doderlein in 

 his remarks on this subject (op. cit. p. 69). It is, indeed, unfortunate that a good many forms of a group 

 of such eminent palseontological and geological importance as the Echinidas should not be in quite 

 a fit condition for reliable identification; but that cannot be helped. It is a fact that the naked tests 

 of several recent species of the three families Echinidce, Toxopneustida' and Echinometridcr cannot be re- 

 ferred with certainty to their proper genus, or even to the family the old genera Echimis and Strongylo- 

 centrotus furnish the most evident proof thereof. But when that is the case with the recent forms, it can 

 certainly not be much better with the fossil forms of such families. We must be glad that it is really 

 possible in very many cases to get a definite result by the examination of the test alone. To point out 

 the case of the genera Loxechinus and Strongyloccntrotus being placed in two different families, as a proof 

 that the use of pedicellarise in classification ^fausse toutes les analogies , seems to me as unfortunate as 

 the designation of the pedicellarise as < moins specialises*. To unite Loxechinus and Strongylocentrotus 

 on account of their both being polyporous (which, I think, is Lambert's reason for doing so) seems 

 to me to be an overestimation of a character which has beyond doubt been developed separately in 

 different groups (Part I. p. 132 33; Doderlein op. cit. p. 203). As for the other case pointed out by 

 Lambert as an unfortunate result of my classification, the placing in different families of Parasalenia 

 and Gon/opygus 1 , I admit that I am not personally acquainted with the fossil Goniopygus, and it may 

 be quite possible that I have been mistaken in placing it in the family Arbaciidez ; but since it is 

 stated to have its ambulacra composed after the diadematoid type, I fail to see how it could be so 

 very closely related to Parasalenia, which has its ambulacra composed after the echinoid type. The 

 pretended close relationship between Goniopygus and Parasalenia seems to me more founded on false 

 analogies than their separation in two different families. And in any case this classificatory result was 

 not reached by the study of pedicellarise, Goniopygus being only known as fossil. Finally, when 

 Lambert marks the pedicellarise as moins specialices*, I really wonder how these organs, which 

 exhibit so great a richness of forms, in many cases no less than four or five different kinds being 

 found in the same specimen, and so exquisite an anatomical and histological structure, could be thus 

 characterized. And I do not see the reason why it should be wrong to use the same classificatory 

 principles for the lower animals which have proved good for the higher and more -.perfectionnes > animals. 

 Upon the whole, I do not see that in all the critical remarks against my classification set forth 

 by Professors Agassiz, Bell and Lambert there is any real, principal objection. I have no doubt 

 that those who will take the trouble to make a careful study of the pedicellarise in the different forms, 

 especially the regular Echini of the families Echinidcp, Toxopneustida: and Echinometrida:, and not be 

 satisfied with literary criticisms alone without a study of the objects themselves, will agree with at 

 least the main results reached by me. The fact that Dr. de Meijere and, above all, Professor Doder- 

 lein after his extensive studies accept my results in the main points makes me confident that my 

 method, which is, indeed, to take all the characters available for systematic purposes into consideration, 

 and to find out by a comparative study of as man}' forms as possible the systematic value of the 

 different characters, will ultimately prove the right one. 



' Pelage & Herouard. Traite de Zoologie concrete. III. p. 238, 245. 



4* 



