ENTOMOLOGY

78 SANITARY ENTOMOLOGYof Geotropes stercorarius (possibly the larva of Physocephalus setralatus),Filaria ephemeridarom in the abdominal cavity of the larvae ofEphemera vUlgata and Oligoneuria rhenana, Filara rytipleuritis (ofMagalhaes, 1900, not Deslongchamps, 18!!4) in the abdominal cavity ofPeriplatneta americana (possibly a Gongylonema according to Seurat),Fila1'ia BtomOll:eos in Stomoxys caZcitrans (possibly the larva of Habronemamicrostoma), MastophoruB echiuruB, and CephalacanthuB monacanthusin Tenebrio molitor (probably larvae of' Protospirora muriB),M astophorus gZobocaudatus and Cephalacan.thus triacanthus inGeotrupes stercorarius (possibly larvae of Physocephalus sexalatus).4. M erm.ithidae. .These worms which resemble the nematodes and are usually groupedwith them are not known to be of importance in medical zoology. Onespecies, of uncertain identity, is of interest, however, as it is the so-called"cabbage snake" whose presence among the leaves of cabbage has alarmedpeople who have encountered it. This worm, like others of the samefamily, undoubtedly passes through a portion of its development in thebody of an insect, probably one of the common caterpillars that attackcabbage. Similar worms have been found in apples.GORDIACEA OR HORSE-HAIR WORMSThe Gordiacea or horse-hair worms (as which they are popularlyknown from the superstitious belid that they fre animated horse hairs)are of medical interest because several species have been recorded asparasites of man. They gain entrance to the alimentary tract by beingswallowed in drinking water. The adults are of not uncommon occurrencein springs and other surface waters. When swallowed by humanbeings they are usually soon vomited up but they have in some casesapparently survived in the intestine for several months before they werefinally expelled. In some species, and probably in all, insects serve ashosts for the larval stages. ' The adults deposit their eggs in the waterin which they live. The larvae hatching from the eggs enter the bodiesof insects such as grasshoppers (as for example, in the case of Gordiusrobustus) or crickets (as for example, in the case of Paragordius varius)or in the case of other species they may enter aquatic insect larvae,which may later be devoured by carnivorous water insects. In the latterthe worms undergo their development until they have reached or approachedmaturity when they burst out of the infested insect and escapeinto the water. The following species of Gordiacea have been recordedas accidental parasites of man: Gordius aquaticus, G. chilensis, Para-