60 Prof. C. Claus on the 



according to Lankester, is " simply repeating a statement by 

 me " &c. ; and when I remark, " Accordingly the roots of 

 the old Gigantostraca and Xiphosura may meet in a common 

 origin " &c., and further, " Besides these two series of 

 Arthropoda, probably united at the base, we have then to 

 distinguish, as a third series of forms, that of the Insecta and 

 Myriapoda, for the derivation of which the remarkable An- 

 nelid-like Onychophora [Peripatus) appear to be possibly of 

 great significance," — opinions which, as shown above, are 

 already contained in the ' Grundziige,' — our author does not 

 hesitate to comment as follows upon these statements : — 

 " Proceeding to formulate the conclusions lohich he has taken 

 hodily from me as to the ])robable genealogy of the chief 

 groups of the Arthropoda, Prof. Claus states that the stem 

 of the Crustacea and that of the Arachnida are united at the 

 base, whilst the Insecta Hexapoda and Myriapoda form a 

 third series, ' for the derivation of which the remarkable An- 

 nelid-like Onychophora [Peripatus) appear to be so signifi- 

 cant.' " I will here take no notice of the misrepresentation 

 which my expression with reference to the Onychophora has 

 undergone in the English translation cited by Lankester by 

 the omission of the word " possibly," by which I wished to 



* 



indicate that the Onychophora-question is still an open one 

 and will confine myself to the demonstration of the diffierence 

 of this derivation from the genealogical tree which Ray 

 Lankester has sketched in his Limulus-&xiic\Q. He says, 

 indeed, " This is a simple and direct description in words of 

 the genealogical tree of the Arthropoda at the end of my 

 article ' L/mi^^^s an Arachnid,' " bat unconsciously gives up 

 this opinion in the following phrase, which runs : — " with 

 this diff"erence, that whilst I have represented the Crustacea 

 and the Arachnida as two main stems with a common base, 

 and Peripatus as a third and independent stem, I have indi- 

 cated a hesitation to decide on referring the Insecta Hexa- 

 poda and Myriapoda to the stem of Peripatus absolutely, and 

 have considered the possibility of their derivation from either 

 the Arthrostracous Crustacea or the tracheate Arachnida." 

 If I wished to embody the genealogical affinities of the three 

 established Arthropod series in the form of a genealogical 

 tree I should have to choose some such scheme as the follow- 

 ing, which, as will be seen from the copy of Hay Lankester's 

 genealogical tree of the Arthropoda placed beside it, presents 

 a somewhat different appearance : — 



* [The quotation in Prof. Lankester's paper was taken from the abridg- 

 ment of Prof. Olaus's note in this Journal, so that the omission of the 

 word " possibly " is hardly to be charged upon Prof. Lankester. To us 

 the " moglicherweise " seemed quite unnecessary, and indeed redundant, 

 in the case of a group which only " appeared " to be of great signihcauce; 

 it certainly did not convey the idea above ascribed to it. — Eds.J 



