I 



I 



the Classification of OribatidjB. 35 



Lists of local fauna are very useful, and aoarologlsts will 

 be glad to have one of the Dutch species, which have not 

 been before recorded ; although we could scarcely anticipate 

 that they would vary much from those of Germany and 

 England, as the distribution of these minute beings is 

 usually wide ; but when, out of 68 species, 25 are inserted 

 thus : " Orihates sp.," without a word of description or any 

 figure, and three thus, "Gen.? sp. ?" also without description 

 or figure, I fear that the value of the list is considerably 

 diminished. 



Dr. Oudemans, in the title above quoted, does not state 

 what value he intends his groups to have; but he calls " Acari" 

 what I imagine he considers the order ; the next lower group 

 (which I suppose he considers the family) he names "Oribatei," 

 and in his list he calls the next still lower group (which is 

 apparently a subfamily) " Phthiracarea." These termina- 

 tions do not appear quite consonant with modern classifi- 

 cation. I imagine him to give the values stated to his 

 groups because he calls those of equivalent values to his 

 Phthiracarea " Nothrinte " and " Oribatinte." Why one 

 subfamily should end in " -ea " and the others in " -ina3 " is 

 not stated. Doubtless Dug^s, writing in 1834, did call his 

 family " Oribatei," raising Latreille's genus Oribata (or Ori- 

 hates) into a family : but Latreille did not call his group Acari, 

 as in the heading of Dr. Oudemans's paper ; he called it first 

 " Acares" and afterwards " Acaridia^," as correctly stated at 

 p. 58; but there it is said, in reference to "Acares," "though 

 this term has a French final syllable it is a pure Latin word " 

 (the italics are mine), " it is the plural of the Latin Acarusy 

 This somewhat surprises me ; I was under the impression 

 that " Acares " was the plural of the French word " Acare," 

 and that the word, although derived through Latin, was from 

 the Greek w^ord for a Mite uKapc, as used by Aristotle, and 

 was founded upon aKapr)<i, uncuttable. 



Dr. Oudemans says that P/ithiracarus, Perty, should be 

 substituted for the genus Tritia, Berlese, because both are 

 founded on a Hophphora with tridactyle claws and Perty's 

 is the earlier. I by no means assert that Tritia is a neces- 

 sary genus ; I did not adopt it, and I am strongly of opinion 

 that the distinction of monodactyle and tridactyle claws has 

 almost entirely broken down as a means of differentiating 

 genera in the Oribatidee, although it is useful iu identifi- 

 cation. I believe that this is now the general opinion ; 

 but if Berlese's genus have any validity it arises from the 

 remarkable fused and elongated genital and anal plates, so 

 exceptional in the Oribatidae, and not from the tridactyle 



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