31 - 
i 
PIERIS I. 
as in male, except that a round black spot appears in submedian interspace on 
primaries. 
Taken by Mr. Henry Edwards, at Virginia City, Nevada, April 1870, on 
flowers of Brassica. Four individuals were taken, and these were the only ones 
seen. This fine species is allied to Protodice and Occidentalis, hut is abundantly 
distinct. 
At the request of Mr. Edwards I have named it in honor (using his own lan- 
guage) “ of one of my earliest and most valued entomological friends, Dr. Ludwig 
Becker, who laid down his noble life in the cause of science in Australia. He was 
attached as naturalist and draughtsman to the great expedition of Burke and 
Wills across the continent from Melbourne to the Gulf of Carpentaria, and died 
of fatigue and privation at Cooper’s Creek, New South Wales, in 1861. The 
friend of Humboldt, Milne Edwards and Owen, he possessed a most observant and 
philosophical mind and his papers upon various subjects connected with his favor- 
ite science testify to his vast and varied erudition. I have always promised myself 
that I would commemorate our friendship by attaching his name to some species 
I might discover, and the present is very appropriate as a few moments before I 
took my first specimen of this Pieris I was thinking very much of Becker and of 
the many happy collecting days we had passed in the forests of Australia.” 
