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not on so extensive a scale. Ratzburg gives a list of no less 

 than fourteen species of Ichneumon parasitic on spiders, while 

 M. Audoin has obtained Microctonits terminalis from Coccinella 

 y-punctata^ L., better known as the Seven-spotted ladybird, 

 and M. Boudier describes two species of Braconidae, the 

 larvae of which burst forth from the abdomens of specimens 

 of Barynotus elevatus and Otiorynchus lignarms in the imago 

 state which had been pierced with pins for preservation, and 

 which spun their cocoons beneath the body of these weevils, 

 attaching them to the pins. As I said before, the Hemiptera 

 are not exempt, for we find the Aphides giving name to a 

 genus called Aphidius. I have myself bred several species 

 from both Hymenoptera and Diptera ; and even in our own 

 houses we have these little visitors come to prey upon the 

 larvae of Ptinidae, as do Spathus clavatmn, and several of the 

 species Cryptus, while others are on the look out for the larvae 

 of Dermestidae, Anthreni, Tineae, and other domestic insects. 

 Orthoptera again are subject to the same kind of parasites, 

 for we find that unsavoury and certainly unpleasant-looking 

 creature, the cockroach, attended to by the family EvanidcB ; 

 and, as though the insect inhabitants of the air and the earth 

 were not enough in number for the Ichneumonidae to revel 

 amongst, we find them actually attacking the residents of the 

 water. In the Entomologist's Magazine, vol. iii., p. 412, we 

 find the following : — ' The female of the remarkable species, 

 Agriotypus armatus, is stated to have been observed on the 

 banks of the Clyde, to descend the sides of the rocks to a 

 considerable depth under the surface of the water, remaining 

 immersed for ten minutes and upwards, and then reappearing 

 without any apparent injury, repeating the operation several 

 times : these subaqueous excursions being probably for the 

 purpose of depositing its eggs in some aquatic larvae.' The 

 Rev, T. A. Marshall mentions 1,186 species of Ichneumonidae 

 as occurring in Great Britain ; while Dr. Packard, in his 

 Guide to the Study of Insects, states that there are over 2,000 

 described species in Europe, and probably an equal number 

 in America, while Gerstaecker estimates that there are 4,000 

 to 5,000 species known ; but to all who are interested in the 

 economy of the Ichneumonidae and its sub-families, I would 

 strongly recommend them to read, if possible, first West- 

 wood's Introduction to the Modern Classification of Insects, and 

 next Dr. Packard's Guide to the Study of Insects, when I have 

 no doubt that they will not only be highly interested, but 

 instructed in the valuable economy of these much maligned, 

 but very beautiful creatures. 



