368 ZOOLOG X. 
the rows of teeth examined. The thoracic and abdominal portions of 
the nervous system, which lies loosely on the floor of the body, can be 
readily found by raising the alimentary canal ; but the brain and infra- 
cesophageal ganglia can best be detected by a longitudinal section of 
the head. The ovaries always lie above the intestine, and the two 
oviducts unite below the nervous cord to form the common duct which 
opens on the ventral side of the third segment in front of the anus, 
which is situated dorsally. Insects should be dissected in a shallow 
pan lined with wax or cork, and the parts floated out ; fresh specimens 
are desirable. The body may also be dissected, each segment with its 
appendages being separated and glued in their true sequence to acard, 
By simply dissecting an insect in this way, the student will acquire a 
valuable knowledge of the external structure of insects, 
LITERATURE OF ARTHROPODA, 
Crustacea.—Milne-Edwards’s Histoire Naturelle des Crustacés. 3 
vols., 1884-1840. Dana’s Crustacea of the U. 8. Exploring Expedi- 
tion. 2 vols., 1852. Gerstaecker’s Arthropoden (in Bronn’s Classen 
und Ordnungen des Thierreichs). 2 vols., 1866-1891. Huxley’s 
The Crayfish, 1880. Packard’s Monograph of North American Phyl- 
lopod Crustacea, 1883. Also the writings of Say, Dohrn, Sars, 
Claus, Brooks, Hagen, Faxon, Smith, Kingsley, etc. 
Podostomata.—Van der Hoeven’s Recherches sur l’Histoire Natu- 
relle des Limules, 1888. Milne-Edwards’s Recherches sur ]’Anatomie 
des Limules, 1872. Packard’s Four Memoirs on the Anatomy and 
Embryology of Limulus, 1872-1891. Kingsley’s Notes on the Em- 
bryology of Limulus, 1885. Also the essays of Walcott, Dohrn, 
Brooks, Lankester, Bruce, and Kishinouye. 
Arachnida.—Hentz’s Spiders of the United States. Boston, 1875. 
Emerton’s Structure and Habits of Spiders, 1883, and his various. 
essays, with those of G. W. and E.G. Peckham. McCook’s American 
Spiders and their Spinning Work. 3 vols., 1889-1892. With the 
works of Walckenaer, Blackwall, Thorell, Simon, Moggridge, Bert- 
kau, Keyserling, Marx, etc. 
Myriopoda.—W 000’s The Myriopoda of North America, 1865. With 
essays by Newport, Harger, Latzel, Haase, Packard, etc. 
Insecta,—Kirby and Spence’s Introduction to Entomology. 4 vols., 
1828. Burmeister’s Manual of Entomology, 1836. Westwood’s Mod- 
ern Classification of Insects. 2 vols., 1889-1840. Harris’s Treatise on 
Insects injurious to Vegetation, 1886. Packard’s Guide to the Study 
of Insects, 1888. Packard’s Entomology for Beginners. New York, 
1890. Graber’s Die Insekten, 1877. Kolbe’s Einfithrung in die 
Kenntniss der Insekten, 1889-1892. Lubbock’s Ants, Bees, and Wasps, 
1882. For economic entomology, the works of Harris, Fitch, Riley, 
Le Baron, Lintner, etc.; also for journals, Insect Life, Washington; 
Psyche, Cambridge, Mass.; Canadian Entomologist, etc. 
