C. H. TYLER TOWNSEND — BIOGEOGRAPHY OF MEXICO, ETC. 53 
can not now be said. The writer has in view a earefnl investigation di 
the flora and fauna of White Mountain, from its base to its summit. 
Full collections will be made, and the slopes thoroughly worked all the 
way to the summit. 
Tile Interrelations of the Diptera and the Flora. — Some 
plants that were collected by Professor E. 0. Wooton and the writer, at 
different times, in this region, and on which diptera were taken, have 
been determined and will be of interest in this connection. Those plants 
collected by Professor Wooton are so mentioned. The species of Diptera, 
so far as determined by the writer, are given under the head of each 
plant, but the mass of them have still to be worked up. Some diptera 
were taken by Professor Wooton, and are so noted; otherwise they were 
all collected by the writer. I am indebted to Professor Wooton for the 
determinations of most of the plants, and also for the elevations, taken 
by aneroid, of the localities where his own specimens were collected. 
The names of the plants and diptera follow: 
1. Thely podium linearifolium Wats. — Blazer’s Mill, about 6200 feet, 
October 2. 
2. Erysimum asperum Dc. — Collected on the Ruidoso, 6500 feet, July 
3, by Professor Wooton, who took on its flowers: 
Oncomyia sp. — Same locality and date. 
3. Rhus glabra Linn. — This plant was collected by Profe.^ jr Wooton 
on the Ruidoso, at 6600 feet, July 10. The locality is well up above 
Dowling’s Mill. The following Diptera were taken by Professor Wooton 
on the flowers. They are all same locality, elevation, and date: 
1. Pipiza occidentals Towns, (n. sp.). 
2. Baccha lemur OS. 
3. Chrysochlamys croesus OS. 
4. Milesia bella Towns, (n. sp.). 
r 5. Dejeania corpulent a Wd. 
' 6. Jurinia lateralis Mcq. 
^ 7. Echinomyia thomsoni Will. 
- 8. Echinomyia neglecta Towns. 
4. Philadelphia serpyllifolius Gray. — Collected on the Ruidoso by 
Professor Wooton, June 30, probably about 6400 feet. He took on its 
flowers: 
Volucella anna Will. — Same locality and date. 
5. Bigelovia graveolens var. glabrata. — This was so determined by 
Prof. J. K. Small, of Columbia University. Specimens were later sent 
to Miss Alice Eastwood, who thought at first sight that it might prove 
to be a different variety, but her conclusion has not yet reached me. 
This Bigelovia grows in profusion all along the stream of the Rio Tula- 
