ECHINOIDEA. II. 



27 



not be found in the fossil forms is of primar\- 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 011 this snbject (op. cit. p. 69). It is, indeed, unfortunate that a good many forms of a group 

 of such eminent palæontological and geological importance as the Echinidæ should not be in quite 

 a fit condition for reliable identification; but that cannot be helped. It is a faet that tlie uaked tests 

 of several recent species of the three families Echinidcc. Toxopneustida: and Echniomrtridw cannot be re- 

 ferred with certaint\' to their proper genus, or even to the famih' — the old genera Ecliiinis and Stroiigylo- 

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

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

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

 the case of the genera Loxcchiiius and Sfrongyloccntrotns being placed in two different families, as a proof 

 that the use of pedicellariæ in classification fausse toutes les analogies , seenis to me as unfortunate as 

 the designation of the pedicellariæ as moins spécialisés . To unite Loxec/iiiit/s and Strongyhcentrotiis 

 OU account of their both being polyporous (which, I think, is Lambert's reasou for doing so| seems 

 to nie to be an o\'erestimatiou of a character which has beyond doubt been de\eloped separately in 

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

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

 and Goniopygiis\ I admit that I am not personalh' acquaiuted with the fossil Goiiiopygus. and it ma>- 

 be quite possible that I have beeu mistakeu in placing it in the famih' Arbaciidæ ; 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 Parasalniia. which has its ambulacra composed after the echinoid type. The 

 pretended close relationship between Goiiiopygus and Parasalcnia seems to me more founded ou false 

 analogies thau their separation in two different families. And in auy case this classificator>- result was 

 not reached b\- the stud\- of pedicellariæ, Goniopygiis being ouly known as fossil. — Finally, wheu 

 Iv amber t marks the pedicellariæ as moins spécialicés-, I really wonder how these organs, which 

 exhibit so great a richness of forms, iu man\- cases uo less thau four or fi\e different kinds being 

 found iu the same specimen, and so exquisite au auatomical and histological structure, could be thus 

 characterized. And I do not see the reason wh\- it should be wroug to use the same classificatory 

 priuciples for the lower animals which have proved good for the higher and more perfectionnés* animals. 

 Upon the whole, I do not see that in all the critical remarks agaiust m\- classification set forth 

 by Professors Agassiz, Bell and Lambert there is auy real, principal objection. I have uo doubt 

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

 especially the regular Echini of the families Echinidw. Toxopncitstidæ and Echiiioi/icfridæ. 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 faet that Dr de Meijere and, above all, Professor Doder- 

 lein after his extensive studies accept m\' results in the main points makes me confideut that m\- 

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

 and to find out by a comparative stud\' of as manv forms as possible the S)'stematic valne of the 

 different characters, will ultimately pro\e the right one. 



' Delage & Hérouard. Traité ile Zoologie concréte. III. p. 23S, 245. 



4* 



