12 BRITISH TYROGLYPHID^E. 



two hypopial nymplis, some species are not, I think, 

 identifiable. 



E. Hering was the next author. His paper* was 

 lodged at the Academy on September 30th, 1835, but 

 does not appear to have been published until 1838. 

 It chiefly treats of the parasitic Sarcoptidae, as its 

 name implies, but it is interesting and necessary to the 

 student of the Tyroglyphida3 as being that which 

 originated the important genus Grlycyphagus ; it also 

 contains a new species called Acarus passularum, which 

 is somewhat similar to aiionymus, upon which the 

 genus Carpoglyphus was subsequently founded. In 

 my opinion, however, the two species are not identical. 



F. Dujardin, in 1849, is the next author who need be 

 noticed. His paper f referred solely to the hypopial 

 stage of the creatures. Dujardin saw that the creatures 

 were immature, but he was entirely in error as to his 

 principal contention ; this, however, is fully discussed 

 in the chapter of this book on development, and there- 

 fore need not occupy space here. Dujardin also 

 described various Hypopi which he had found, and 

 illustrated them with drawings as beautifully executed 

 as those of that keen-eyed observer generally were ; 

 one of his creatures is evidently a homopial Hypopus. 



A. Laboulbene, in 1852, published a short paper, { 

 which was subsequently supplemented by a more elabo- 

 rate one written in conjunction with C. Robin. These 

 papers are interesting, as the earlier is the first notice 

 of any of the creatures forming the present genus 

 Histiogaster, || and also because H. entomopliagus has 



* "Die Krazmilben von Thieve und einige verwandte Arten," in 

 ' N. Acta Ac. Leop.,' vol. xviii, pt. ii, pp. 575 624. 



"|" " Memoire sur quelques Acariens sans bouche dont on a'fait le 

 genre Hypopus et qui sont le premier age des Gamases," in ' Ann. Sci. 

 Nat.,' 1849, ser. 3, t. xii, pp. 244250. " Additions au mcmoire sur 

 les Hypopus" ibid., pp. 259 265. 



J " Description de V Acarus entomophagus" in ' Ann. Soc. ent. 

 France,' 1852, Bull., p. 54. 



"Description de V Acarus (Tyroglyphus) entomopliagus, Laboulbene 

 et Observations anatomiques sur le genre Tyroglyphus," in ' Ann. Soc. 

 ent. France,' 1862, ser. 4, t. ii, pp. 317338, pi. x. 



|| Berlese (A. M. S. Crypt.) wishes to confine the genus Histiogaster 



