20 Transactions of the Society. 



to which the ravages of a Coccus (MytiJaspis pomicorticis of 

 American authors,* which they popularly call " the mussel- 

 shell bark-louse ") were being carried upon their apple-trees. This 

 naturally attracted the attention of State-entomologists amongst 

 others, and Dr. Shimer wrote two articles on the subject in the 

 'Transactions' of the Illinois Horticultural Society in the years 

 18G8 and 18f)9. In these papers he describes an Acarus, which 

 he calls A. mains, and which, as far as I can ascertain from Riley's 

 abstract, for I have not been able to obtain the original paper 

 here, Dr. Shimer appears to consider as an enemy of the Coccus and 

 therefore an ally of the cultivator. Dr. Shimer describes this 

 Acarns and also mentions that he found with it a six-legged 

 form which he treats as a separate species and names A. Walshii, 

 but which doubtless was only the larval form of T. mains. 



In the year 1873, the spread of the Coccus in Georgia was 

 submitted to the notice of Mr. Eiley who published a very interest- 

 ing notice of the result of his investigations.! In this article he 

 figures and slightly describes an Acariis which he considers, 

 apparently from information received from others, and not from 

 personal investigation, to be destructive of the bark-louse. Eiley 

 says, " It may be a form of the A. mains of Shimer," but ho then 

 proceeds to give such excellent reasons for not considering it to be 

 identical, that I have ventured to treat it as a different species, 

 although Eiley himself does not name it but leaves it to be looked 

 upon as Shimer 's species ; he winds up his article, or rather foot- 

 note, for that is all that he writes upon the Acarus, by saying, 

 "It apparently belongs to the genus Dermaleichus." This is 

 manifestly an error, as the Dermaleichi are not only all of them 

 bird-parasites, but Eiley 's figure would be sufficient to show that 

 the mite was one of the Tyroglyphidse. Eiley does not say any- 

 thing about sexes, nor immature forms, nor does he desciibe or 

 figure two sorts of adult which might be male and female ; but his 

 figures, which are very good, although on a small scale, are 

 evidently drawn from a female specimen ; this sex is usually much 

 more abundant than the male in the Trjroglyphiclse. 



Andrew Murray! reproduces Eiley 's figures, shortly abstracts 

 his notice, and correctly places the creature among the Tijro- 

 glypliidse ; he says, however, that it is " either a Tyroglyphus or a 

 Bhizoghjphus. Mr, Eiley 's beautiful figure is not on a sufiiciently 

 large scale to allow us to make out which." Murray would seem 

 from this rather to have overlooked the fact that Eiley 's figures are 

 helped by his description in this respect. Murray, however, in spite 



* The usual name here for tliis creature is Aspidotus conchiformis, but it has 

 also been called Coccus arhorcim linearis, Diaspis linearis, Chermes conchiformis, &c. 

 t Fifth Missouri Report, 1873, p. 87. 

 X 'Economic Entomology. Aptera,' 1876, p. 275. 



