CIDARTD^. 19 



constantly finds '' a fine demonstration of the trustwoiiliiness of tlio state- 

 ments liitlierto found in the literature with regurd to the occurrence and 

 distribution of these animals"! Once given his genera, the rest natur.dlv 

 follows, and we have nothing left of what has preceded. 



It appears childish to be constantly lamenting, as do Dr. Mortensen 

 and M. de Meijere, the loss of a specimen, if examined by the old method.-., 

 necessary for the examination of the test, and of the actinal and abactinal 

 systems. Surely we cannot welcome a method which deliberately saves a 

 specimen in order to remain ignorant of its structure, or which would 

 necessitate the definition of an Echiuoid to be that of an animal consistinti 

 of a number of pedicellaria? of variable forms, with which are connected a 

 test covered with spines, tubercles, and all the other useless and su[)er- 

 nnmerary structures which have thus far been studied in the classification 

 of the Echinoids, to the great detriment of the pedicellariae. 



When a living species is referred to a fossil genns, Dr. Mortensen on 

 principle denies the accuracy of such a proceeding, and demands the 

 adoption of synonyms, as in the case of Gli/ptocidaris, Ccenopedina, and 

 of Goniocidaris and others. But he is not consistent in this general rejec- 

 tion of generic names of fossil Echini, as he retains Arbacina, Porocidans, 

 Stereocidaris, and others, for no apparent reasons. 



As M. de Meijere well says, Dr. Mortensen's methods naturally lead to 

 an infinitesimal splitting up of the older genera, to the establishment of 

 genera based on a single structural feature, and to the loss of the rela- 

 tionship of the species they contain. 



It does not occur to Dr. Mortensen that differences of opinion are 

 possible, that points of view other than his own have any value, and that 

 perhaps the last word has not been said regarding the affinities of the 

 Echinoids. The height of absurdity is finally reached when we are told 

 that nothing can be said of the affinities of species of which pedicellariaB 

 have not been examined (by him). 



