480 
Head of Psylla mali 
Crawford, D. L. (1914). A Monograph of the Jumping Plant-Lice or Psyllidae of the New 
World. United States Nat. Mus. Bull. 85. 
Davidson, J. (1913). The Structure and Biology of Schizoneura lanigera Haus. Pt I. The 
apterous viviparous female. Quart. Journ. Microsc. Sci. lviii. 653-701, Pis. 38-42. 
- (1914). On the Mouth Parts and Mechanism of Suction in Schizoneura lanigera. 
Journ. Linn. Soc. xxxii. 307-330, Pis. 24, 25. 
Dreyfus, L. (1894). Zu J. Krassilstschicks Mitteilungen uber die vergleichende Anat. u. 
Systematik der Phytophthires mit besondere Bezugnahme auf die Phylloxeriden. Zool. 
Anz. xvn. 205-208, 221-235, 237-242. 
Geise, O. (1883). Mundtheile der Rhynchoten. Arch. f. Naturg. xlix. 315-373, Pl. X. 
Grove, A. J. (1909). The Anatomy of Siphonophora rosarurn Walk. Pt I. The apterous 
viviparous stage. Parasitology, n. 1-28, PI. I. 
Krassilstschick, J. (1892). Zur Anatomie der Phytophthires. Zool. Anz. xv. 217-223. 
- (1893). Zur Anatomie und Histologie der Phylloxera Horae ent. Boss. xvn. 1-37, 
Pis. I, II 
Marlatt, C. L. (1895). The Hemipterous Mouth. Proc. ent. Soc. Washington, m. 241-249. 
Meek, W. J. (1903). On the Mouth Parts of the Hemiptera. Bull, of Univ. Kansas, it. 
257-277, Pis. VII-XI. 
Mordwilko, A. (1895). Zur Anatomie der Pflanzenlause. Zool. Anz. xvih. 345-364, 402. 
Muir, F. and Kershaw, J. C. (1911 a). On the Homologies and Mechanism of the Mouth 
Parts of Hemiptera. Psyche, xvm. 1-12, Pis. I-V. 
- (1911 h ). On the Later Embryological Stages of the Head of Pristhesancus papuensis. 
Psyche, xvih. 75-79, Pis. IX and X. 
-- (1912). The Development of the Mouth Parts in the Hemiptera with Observations 
on the Embryo of Siphanta. Psyche, xix. 77-89. 
Nuttall, G. H. F. and Shipley, A. E. (1901-1903). The Structure and Biology of Anopheles 
{A. maculipennis). Journ. of Hyg. i. 45-77, 269-276, 451-484; n. 58-84; hi. 166-215. 
Smith, J. B. (1892). The Structure of the Hemipterous Mouth. Science, i. 189-190. 
- (1896). An Essay on the Development of the Mouth Parts of certain Insects. Trans 
Amer. Phil. Soc. xix. 175-198, 3 pis. 
- (1898). The Mouth Parts of the Rhynchota. Science, vti. 374-376. 
Stough, H. B. (1910). The Hackberry Psylla, Pachypsylla cettidis mammae Riley. A Study 
in Comparative Morphology. Kansas Univ. Sci. Bull. v. 121-164, Pis. XXVI-XXXV. 
Witlaczil, E. (1882). Zur Anatomie der Aphiden. Arb. a. d. Zool. Inst. Univ. Wien, iv. 
379, 3 pis. 
- (1885). Die Anatomie der Psylliden. Zeitschr. f. wiss. Zool. xlii. 562-638, Pis. 
XX—XXII. 
- (1886). Zur Morphologie und Anatomie der Cocciden. Ibid, xliii. 149-174, PI. V. 
