1915] The Head and Mouth-Parts of Thysanoptera 57 
BIBLIOGRAPHY. 
Berlese, Antonio.—Gli Insetti, loro organizzazione, sviluppo, abitudini e rapporti 
coll’uomo. Vol. I., Milan, 1909, 153. 
Bugnion, E.—L’Appareil Salivaire des Hemipteres. Arch. D’Anat. Mic. Vol. 10, 
1908, 227-268; Vol. 11, 1910, 435-456. 
Faure-Fremiet, E.—Contribution a L’Etude des Glandes Labiales des Hydrocor- 
ises. Ann. des Sci. Nat. Zool., N. S. 9, Vol. 12, 1910, 217-239. 
Garman, H.—The Mouth-parts of the Thysanoptera. Bul. of the Essex Inst. 
Vol. 22, 1890, 24-27. 
Hinds, W. E.—Contribution to a Monograph of the Insects of the Order Thy- 
sanoptera Inhabiting North America. Proc. of the U. S. Nat. Mus. Vol. 26, 
1903, 79-242. 
Jordan, Karl.—Anatomie und Biologie der Physapoda. Zeit. fur Wiss. Zool. Vol. 
47, 1888, 541-620. 
Muir, F. and Kershaw, J. C.—On the Homologies and Mechanism of the Mouth- 
parts of Hemiptera. Psyche. Vol. 18, 1911, 9-10. 
Uzel, Heinrich.—Monographie der Ordnung Thysanoptera. 1895. 
EXPLANATION OF PLATES. 
PrATE. i: 
Fig. 1. Ventral aspect of the head of Heliothrips femoralis. 
Fig. 2. Left later:l aspect of the head of Leliothrips femoralis. 
Fir. 3. Left lateral aspect of the mouth-cone of Thrips physapus. 
Fig. 4. Antenna of Heliothrips femoralis. 
Fig. 5. Right lateral aspect of the head of Heliothrips femoralis. 
Fig. 6. Right lateral aspect of the mouth-cone of Thrips physapus. 
Fig. 7. Dorsal aspect of the head-capsule of Heliothrips femoralis. 
PLATE II. 
Fig. 8. Ventral aspect of the head of Cephalothrips yucce. 
Fig. 9. Dorsal aspect of the head-capsule of Cephalothrips yucce. 
Fig. 10. Antenna of Cephalothrips yucce. 
Fig. 11. Left lateral aspect of the head of Cephalothrips yucce. 
PEAnEe Une 
Fig. 12. Left lateral aspect of the head of the nymph of Heliothrips femoralis. 
Fig. 13. Ventral aspect of the head of the nymph of Heliothrips femoralis. 
Fig. 14. Ental view of a maxillary sclerite of Thrips physapus. 
Fig. 15. Longitudinal section, of the proximal and distal portions of a long, 
salivary gland of Cephalothrips yucce. 
Fig. 16. Longitudinal section of a short, salivary gland of Cephalothrips yucce. 
Fig. 17. . Ventral aspect of the head of the nymph of Cephalothrips yucce. 
Fig. 18. Left lateral aspect of the head of the nymph of Cephalothrips yucce. 
Fig. 19. Right lateral aspect of the head of the nymph of Heliothrips femoralis. 
Fig. 20. Ventral aspect of the head of the semi-pupa of Cephalothrips yucce. 
Fig. 21. Ectal aspect of a maxillary sclerite of Frankliniella tritici. 
