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southwestern states and the west coast of Mexico. I accordingly 
oo from Washington, D. C., on the 19th of February with 
Mr. P. C. Standley and Mr. Paul Russell as assistants, and 
ae about the first of May. 
Field work was begun at Big Spring, Texas, where a beautiful 
new Echinocereus was gathered along with other curious desert 
plants. Short stops were made at Sierra Blanca and El Paso, 
Texas, Agricultural College, New Mexico, and Benson, Arizona 
where about 130 plants, many of them cactuses, were eollee te a 
mn the morning of March 3 we arrived at Hermosillo, the 
pen and principal town of Sonora, Mexico. It is in a fertile 
green valley filled with orange groves and grain fields; but the 
hills are deserts of the Teal kind and here it was that we spent 
most of our time. During the six days at Hermosillo we cated 
about 300 species, including several cactuses. The most interest- 
ing cactuses were Opuntia gosselliana with its ete colored 
joints and very long porrect spines and the very rare little Mamil- 
laria mainae. 
e then proceeded to Guaymas, which is on the Gulf of 
Califor. ere we collected numerous cactuses from tiny 
seen to the giant ‘‘cardons,” of which there are two in 
this vicinity, viz., Pachycereus pecten-aboriginum and P. pringlet. 
Carnegiea gigantea, the giant cactus of Arizona, is also to be 
found on the neighboring hills. This species we — traced 
southward to the hills bordering the valley of the Yaqui River. 
it was not seen south of this river and I am ae to believe 
that this is its southernmost limit. 
From Guaymas we proceeded by train to Alamos, where we 
remained about a week, making daily excursions over the lower 
hills or up the side of Alamos Mountain which is near the town. 
was much surprised to find here a Cephalocereus, but the species 
has not yet been determined. About 475 species were collected. 
A night and a part of the next day were spent at Navajoa, 
where we changed cars for the Southern Pacific Railroad. We 
then proceeded south to San Blas which is the junction of the 
Southern Pacific and Kansas City and Orient roads. With San 
Blas as a base we collected on all the neighboring hills, thence 
