Classification of the Arthropoda. 59 



his, Scorpio, and MygaJe, especially as perfectly similar endo- 

 skelctal structures occur also in the Crustacea? 



Under such circumstances it will hardly be a matter of 

 wonder if I was unable to recognize in Eay Lankester's 

 Limulus-dir\\c\& any advance towards a solution of a problem 

 which has been extant for years, but rather felt compelled to 

 regard it as a failure, so far as it went beyond what was 

 known to his predecessors. Consequently if, in my short 

 communication in the '■ Anzeiger ' of the Academy, I had been 

 able to include any statements upon the literature of the sub- 

 ject, I should certainly have cited Ray Lankester's article only 

 in the above sense, and to show how hasty speculations may 

 shoot beyond the mark. I may, however, admit freely that 

 in the preparation of my short note I had not the least thought 

 of Ray Lankester's Limulus-memoiv , especially as my con- 

 ception of the relations of the Gigantostraca to the Arach- 

 noidea dates much further back, and has nothing at all in 

 common with all the speculations, assertions, and conclusions 

 of the English author. 



Had Ray Lankester been able to treat the few words of my 

 communication with quiet consideration it would have been 

 quite impossible that the contrast of the two views should 

 have escaped him so completely ; with the acuteness peculiar 

 to him he must at once have recognized that I assert some- 

 thing quite different from his conclusions when I arrange the 

 Gigantostraca and the Arachnoidea as descending from them 

 as different classes in a genetic series, while he himself would 

 prove Limidus to be an Arachnid, and imagines that he has 

 proved it. I regarded the relationsliip of the Xiphosura and 

 Arachnoidea as a more distant one; and by placing the 

 Gigantostraca and Arachnoidea in one of the three Arthropod 

 series I by no means affirm the Arachnoidal nature oH Limu- 

 lus any more than I would maintain the Insect nature of 

 Peripatus, which, as a representative of the Onychophora, I 

 placed, with the Myriapoda and Insecta, in the other series. 



3. It must appear quite unintelligible that Ray Lankester 

 was not aware of the great differences which exist between 

 him and myself as to the mode of derivation of the classes of 

 Arthropoda, as also of the contradiction in the interpretation 

 of the antenna, so that he could do my views the honour of 

 regarding them as almost, point by point, adopted from his 

 own. V/hen I asserted in my communication : " Hitherto, 

 evidently, far too much stress has been laid upon this latter 

 agreement [respiration by trachege] in the unfortunate divi- 

 sion of the Arthropoda into Branchiata andTracheata " (and 

 the same thing was previously said in the ' Grundziige '), 

 " without considering that the breathing by air-spaces may 

 have been developed in different ways," &c., this of course. 



