. Economic entomology. Beneficial insects; Insect pests; Thysanura. GALL MITES. 347 CASE similar to those of the Tetranychi. Now the mandible-like objects may be short, stout palpi, but in no other description or figure of Phytoptus that we have seen, is there any sign ever given of them being appendiculated; indeed they are not represented at all in any highly magnified figure of the head that we have seen. Nor can we find anyone who has seen this. His next argument, that, by compression, a curved, long, narrow blade was made to project from the mouth, requires more ehicidation. His last, tha
. Economic entomology. Beneficial insects; Insect pests; Thysanura. GALL MITES. 347 CASE similar to those of the Tetranychi. Now the mandible-like objects may be short, stout palpi, but in no other description or figure of Phytoptus that we have seen, is there any sign ever given of them being appendiculated; indeed they are not represented at all in any highly magnified figure of the head that we have seen. Nor can we find anyone who has seen this. His next argument, that, by compression, a curved, long, narrow blade was made to project from the mouth, requires more ehicidation. His last, that the legs are composed of seven articles, which are proportioned like those of Tetranychus, is erroneous; the legs of the Phytopti being only composed of five articles. But independent of this alto- gether, there is one fact that seems fatal to the idea of these being Tetranychi, or allied to them. The development of the Tetranychi and Trombidiidse, as well as of their allies Hy- drachnidse and Bdellidae, has been thoroughly Leg of phytoptus. ' O ^ Copied from Dr. LGu. wrought out. Many species have been traced through all their stages, and not one has been found whose early stage has not been six-footed, and very like the mature insect. The Tetranychi and their allies may, therefore, we imagine, be eliminated from the number of possible parents of the Phytopti. Next comes M. Scheuten and his Gamasidae. The same objec- tion apphes to his view as to that of Duges. The development of most of the types of Gamasidse is perfectly well known, and has been ascertained to be six-footed in the young, and there is no reason to suppose that those types which have not yet been traced differ from the others in this respect. As to the Sarcoptidae again, the outward resemblance to them is much greater than to any other family of mites. Like them the Phytopti have short thick palpi flanking the mandibles. The number of joints in the legs of both is the same. As the structure of the legs is a
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