APPENDIX NO. 2.— (Continued.)
St. Loots, February 13, 1848. [t Dear Sir: Your letter, together with the package containing the drawings of a iber of most interesting cactacea;, arrived safely here about two weeks ago. On the occasion of my report  on  the botany of Dr.  Wislizenus' voyage,   I have made a refill investigation of the cactacege, of which he brought home with him more than twenty ecies, and have been enabled to  elucidate several  points which had been unknown, or ob-
t     t*                                     ii.i                                     >.ii.i                                   j*    i* ¦                                                       «                       *                                  »                        _
157                            [ 7 ]
of
:etaeeŁe at present cultivated in Europ' amuch smaller proportion in fruit. have ventured to describe some of your species from the drawing; my description, how-r,and the names given by me, must remain doubtful till we are able to obtain some more a to characterize the species. I have written it more for your information than for publi-ion, but if you choose to append it to your published report, I have no objection to it, but ist request you to make such corrections or alterations as your notes or your recollection the plants will enable you to do; for example, as to size, as in some of the drawings no iis mentioned,* in which case I have assumed them to represent the natural size. I liave, convenience sake, numbered the different figures, and shall now proceed to copy for you descriptions and remarks following my numbers.
. Mammillaria.    October 18, 1846; head waters of the Gila, 6,000 feet above the sea. 'roliferons in the highest degree, forming hemispherical masses  often of a diameter three a-half feet; which  are composed of 100—200 different  heads or stems.    Single heads «cal, apparently about 4 or 5 inches high, and 2^—3 inches  in diameter; color, bluish ten; spines white or reddish.
This species appears to be allied to M. vivipara, but is distinguished by the conical heads, i the hemispherical tufts, while ST. vivipara has hemispherical or even depressed heads, forms flat and spreading masses.
It may be an undescribed species, in which case the name of M. aggregata appears to be st appropriate.
I Mammillaria. October 26, 1846. Rare; on the Gila, 3 or 4,000 feet above ihe sea. Apparently a mammillaria, though the habit of the plant is more that of an Echinocereus, tall Echinocerei have the bunches of spines disposed in vertiele ridges, which is not the se in the figure in question. Stems irregularly cylindrical, with divers contractions and idling, about 4—6 inches high, and 1J and 1J inches in diameter, many (in the figure 8,) ¦jm one base.
The name of M. fasciculata would indicate the peculiarity of this species. 3, Mammillaria.    November 4, 1846; abundant.                  ,
Several (fig. 3,) oval stems from one base, 1^—2J inches high, and lj{ inch in diameter; iercles in about 13 rows; spines whitish, short; one small obovate red berry toward the itxnot more than 1^ line long.
lithe figure is correct, this species ought to be distinguished by the name of M. microcar-us I know of no other Mammillaria with such a small fruit.
i Echinocactus Wislizcni.    (Engolm. in Wislizenus' report.)    October 26, 1846. 1«addition to,the description in Dr. W.'s report, which I have drawn up from dried specials, I observe in this figure  that the  species has 21 oblique ribs, is of an oval shape, and isi green color; the ribs are acute, but not compressed, according to the representation of section, and the groves corresponding.
». Echinocactus.    October 25, 1849;  18 inches in diameter.
Height equal to the diameter; shape ventrieose, contracted towards the vertex, therefore •what urceolate; with 21 straight sharp ribs; spines apparently 8, straight, brown, color plant bright green; vertex whitish, (tomentose?) fruit 1 or \\ inches long, oval, yellowish reddish. Seed obovate, obliquely truncated at base, full one line long, black, opaque, jbtlv roughened; embryo curved or hooked, cotyledons aecumbent, partly buried in the «ge farinaceous albumen.
This species is distinct from all other New Mexican species examined by me, and is most siably undescribed. I propose to nams it after its zealous discoverer, who has, surmount-^numberless difficulties, though occupied by severe and arduous duties, found leisure to do irnuch for the advancement of our knowledge of the wild countries traversed by him, ¦iinocactus Emoryi.
<• Cereus.    November 21, 1S46; 3 feet high. There can be but little doubt but that we have hero a species before us, which I have re-
Were the size is not mentioned, the original drawings are tie size of natnre.    W. H. E,