91 
giganteus) which is more abundant northward extends this far 
southward and supposedly beyond on the higher mesas and 
slopes. In the valleys and lower levels its place is taken by 
Fic. 11. Cereus sp. (Pithaya) on island in Bay of Guaymas (see Fig. 10). 
another Ceres which forms a short thick main trunk from which 
a number of high branches arise. This large form extends 
down to sea-level, and is abundant on the islands in the Bay of 
Guaymas, and I was so fortunate as to secure photographs of 
this interesting plant growing within a few feet of clumps of man- 
grove. It is certainly an unusual occurrence to find such large 
xerophytics so near a typical strand form. 
Numbers of species of opuntias, asclepiads, and thorny shrubs 
were found around Guaymas. Adequate transportation facilities 
for freight by land being difficult to secure, collections were 
made almost entirely from row-boats, by the use of which a 
great length of shore line was visited and numbers of succulent 
plants, including “Bisnagas" (Achinocacti) from the islands in 
the harbor were secured. A visit was made to the irrigated 
ranch of Sefior Bustamente, northwest from Guaymas, where 
