287 



Gamasus coleoptratorum L." It is impossible not to be surprised 

 at such a suggestiou of such au able acarologist as Berlese. Iïas 

 he wholly overlooked that Gamasus coleoptratorum has two clorsal 

 shields, whilst G. maritimus of Laboulbène is only protected by oneV 

 The description of Linne's Acarus littoralis does not fit on 

 Gamasus litoralis G. et R. Can. It is probably a Trombidium. 



15. Laelaps (C. L. Kocli). 



The genus Laelaps was created by C. L. Koch in 1836, with 

 Laelaps agilis C. L. Koch as type (Koch, Beu. Cr. Myr. Arachn. 

 4, 19). 



In 1842 Koch took Laelaps hilaris C. L. Koch as type of the 

 genus (Koch, Ueb. des Arachn. Syst. v. 3, p. 88). 



At present we know that this is the sarne animal. 



In 1882 G. et R. Canestrini created the genus Stilochirus for 

 a rnutilated male Acarus, of which the mandibles were very dif- 

 ferent from those of all the known L/aelaptinae. Berlese examined 

 the specimen and described the characters of the genus in August 

 1892 in fase. 70, n°. 13 of his Acari, Myr. et Scorp. hal. The 

 priucipal character is undoubtedly the styliform mandible, which 

 I' will consider as that which distinguishes the genus from all the 

 other genera of Laelaptinae. 



Now T found several males of Laelaps agilis C. L. Koch. Their 

 mandibles are styliform! as 1 will describe below. 



Consequently the mites of C. L. Koch and Canestrini belong 

 to the same genus, which, according to the rules of nomenclature, 

 must, in future, be called Laelaps C. L. Koch. 



16. Laelaps agilis C. L. Koch. 



(With Plate VIII, fig. 9-13). 



Hitherto the male of Laelaps agilis C. L. Koch was unknown. 

 I have found several males on Arvicola arvalis, Mustela vulgaris, etc. 



Frotonympha. I could not distinguish males from females, all 

 having nymphal characters, no genitalia. 



