[575] Nienburg 1908.

[576] Harper 1900.

[577] Guilliermond 1904, p. 60.

[578] Baur 1899.

[579] Sturgis 1890.

[580] Nienburg 1908.

[581] Schwendener 1864.

[582] Wahlberg 1902.

[583] Baur 1904.

[584] Brown 1911.