180 Prof. E. R. Lankester's Bejoinder to Prof. Clans. 



and Prof. Edouard Van Beneden, can be surprised either at 

 Professor Claus's objectionable article on the classification of 

 the Arthropoda or at his attempt to justify it. 



1. Professor Claus now tells us (Ann. & Mag. Nat. Hist. 

 July 1886, p. 56) that he did recognize the relationship of 

 Limulus to the Arachnida in his handbook of 1880, and 

 quotes a passage to prove this. The passage merely proves 

 that Claus was not ignorant of the general views of Huxley, 

 Dohrn, and Ed. Van Beneden. The fact remains that he 

 classified the Gigantostraca under the Crustacea, and in his 

 description of that group said nothing of their affinities with 

 the Arachnida. 



2. Professor Claus endeavours to saddle me with an opinion 

 as to the existence of twelve segments in the abdominal cara- 

 pace of Limulus which I have never ex[iresscd, and quotes 

 with approval (p. 57) some remarks made by Packard on this 

 subject, which do not require refutation, but obviously are 

 due to misconception. 



It is important to note that Prof. Claus even now regards 

 the attempt to refer the lung-sacs of the Scorpion to the intro- 

 verted branchial lamellas of Limuloid ancestors as " mere 

 trifling." He also endorses Packard's objections to my inter- 

 pretation of the relationship of the brain and of the simple 

 and compound eyes in Limulus and Scorpio. Time will 

 show whether the views now rejected by Claus are correct 

 or not. I much prefer to find him expressing a divergence 

 between his views and my own to having to look on whilst 

 he puts forward as new, without any acknowledgment or 

 reference, views which have been previously made the subject 

 of special treatises by his contemporaries. 



3. Professor Claus has no reply to the statement made by 

 me that he has, in his paper in the ' Anzeiger ' of the Vienna 

 Academy, announced the view that the Acarina are degenerate 

 Arachnida as a new conclusion of his own, whereas I had 

 previously formulated this conclusion — and that, too, as one 

 result of a general consideration of the genetic relationships 

 of the Arthropoda, which is in all essential features tlie same 

 as that which he has recently put forward as a new thing of 

 his own. 



4. The phrase on p. 59, " and the same thing was previously 

 said in the ' GrundzUge,' " appears to me to be entirely incon- 

 sistent with fact. 



5. The attempt is made by Claus on p. 61 to show that 

 the genealogical tree of the Arthropoda described by him is 

 after all diftcrent from that constructed by me. No one who 

 considers the matter attentively will be deceived by the different 



