72 CALIFORNIA ACADEMY OF SCIENCES. [Proc. 3D Ser. 



degree of isolation. The interesting description of the 

 country, which Professor Cockerell has written, throws 

 considerable light on the probable history of these plants. 



CEnothera tubicula filifolia, var. nov. 

 Plate VI, Fig. i. 



Stems slender, suffruticose; older parts with grayish brown, shreddy epi- 

 dermis; younger parts and leaves slightly glandular, hoary-puberulent, with 

 spreading short white hairs; leaves sessile, becoming almost terete with the 

 involute margins, 5-15 mm. long, \-\\ mm. or less wide, crowded at the ends 

 of the branches and in small rosulate clusters in the axils; calyx-tube 3-3^ cm. 

 long, funnel-form lobes spotted with dark purple, i cm. long, 4 mm. broad, 

 with pointed tip i mm. long; corolla 3^ cm. in diameter, yellow, tinged with 

 white when withered, petals rhomboidal, slightly acuminate, upper margin 

 wavy; stamens with anthers i mm. broad, 7 mm. long, equalling the filaments; 



The exact extent of the White Sands I do not know, but they are probably 

 about forty miles long and a good many miles across. They lie to the east 

 of the San Andreas range of mountains. They are composed of pure gypsum, 

 undoubtedly deposited from a salt water lake, which must have been shut off 

 from the sea and by degrees have dried up. Prof. A. Goss, of the N. M. 

 Agricultural Experiment Station, has pointed out to me, that as the lake 

 dried up, the gypsum would be precipitated early, being comparatively insol- 

 uble. Eventually the other salts would be deposited on the top of it. The 

 more soluble salts have long ago been washed away, and we have remaining 

 the beds of gypsum, which now rise considerably above the surrounding 

 plain, the latter doubtless having been lowered by gradual denudation. While 

 the plain itself contains a great quantity of gypsum, the banks are perfectly dis- 

 tinct and well defined— as well defined as a miner's dump. Somewhere in 

 the sands, I am informed, there is a spring, and water is nowhere far from 

 the surface. 



It might be thought that no vegetation would grow on pure gypsum sand, 

 but there is a scattered growth, consisting of various shrubby and herbaceous 

 plants. I even found a small poplar, which looked to me like Populus tremu- 

 loides, though not typical; the poplar of the surrounding country, at least of 

 the Rio Grande Valley, across the mountains, is P. fremonfii, never P. 

 tremidoides, at so low a level. One of the commonest shrubby plants on the 

 sands is a Rhus, while a Bigelovia grows to a considerable size. When, last 

 autumn, I visited this locality with Prof. C. H. T. Townsend, I was able to 

 collect a few plants and insects; and my companion went somewhat further 

 than I did, with the result of collecting two species of bees in quantity, and 

 some other insects, which I had missed. Unfortunately, I was anything but 

 well at the time, and we could not delay more than a short while, so that 

 what was obtained was a mere fragmentary sample of the actual fauna and 



flora of the sands. 



T. D. A. Cockerell. 

 Mesilla, N. M., Feb. 28, 1897. 



