Numenchdure of Genera &c. in the Orlbatkla3. oil 



as Acai'us corticalis, de Geer, t. vii. pi. viii. fi<^. 1, wliicli 

 certainly is not what we now call D. geniculatusj and is not a 

 Danueus at all, and which cannot well have been Linnajus's 

 species, because, meai^re as the Linnean description is, it is 

 inconsistent with A. corticalis of de Geer. The fact is tiiat 

 no one can say, even approximately, what the A. genicidatas 

 of Linnajus was. Latreille evidently did not know any bitter 

 than we do, and he mixed up several totally inconsistent 

 species under the name. It was only in 1835 tliat C. L. Koch 

 described a species in a manner which could be recognized, 

 and adopted the Linnean specific name and the genus 

 Dnma^HS for it; but this cannot affect priorities in 1802- 

 1803 ; and there is not any reason to suppose that it is tiie 

 Linnean species. A. genicuhUus having failed as a type 

 and the definition of the genus being insufficient, what can 

 we take as the type ? It would be the species put first by 

 Latreille in his next work in 1803 as above quoted, viz., 

 Acarus coleojitratus, if that be a sufficiently described species. 

 Dr. Oudenians says tiiat it is, and that " Linn^'s description 

 of his .[c'J7-iis coleoptratus fits perfectly on Oribates ovalisy 

 Koch." Jf that be so, then it appears to me that Dr. Ou le- 

 mans has proved conclusively that the sense in whicli 

 acarologists use the genus Oribata is correct, and that if it; 

 were changed into Noiaspis, as Dr. Oudemans suggests, it 

 would be wrong. I fear, however, that 1 cannot accept this, 

 simple method of deciding the point, because it seems to ine 

 that the Linnean description of A. coleo/jtratus is as im- 

 possible to identify as that of A. geniculatus ; it is, " Acarus 

 uter, lateribus nigro-subcoleoptrutus.^' How Dr. Oudemans 

 makes this fit Onbala ovulis or anything else is quite beyond 

 my comprehension. The fact is that all that can be said is 

 that both Oribata, Latreille, and Notaspis, Hermann, were 

 intended to include the whole of tlie Oribatidie, that the types 

 utterly broke down, and that until Koch defined the former 

 and IS'icolet the latter, the genera were undefined, and there- 

 fore the names as at present used are correct. 



Dr. Oudemans then suggests that the genus Sarrarius may 

 have to be changed into Gustavia because he is of opinion 

 that Gustavia sal, Kramer, is likely to prove to be a nymph 

 of a Serrarius ; of this no evidence is offered. Kramer him- 

 self" expressly said that it was not one of the Oiibatidfe, and 

 the four-jointei palpi seem to render it unlikely that ib is. 

 Even if it were, it seems to me that all existing authorities 

 negative the validity of names of Acarina, whether generic or 

 specific, wliich are founded on immature types ; but as I have 

 lately fully discussed this question in ' British Tyroglyphida?,' 

 Kay t5ociety, 1901, pp. 185-187, I will not repeat it hero. 



