A GIGAXTrC EQUrSETUM. 123 
finding either of the plants on the fine range of precipitous rocks ex- 
tending right and left from the chasm called Twli Ddu ; for the sides 
of the chasm itself are absolutely inaccessible, and I presume that Mr. 
Griffith (Smith's correspondent) extended the Welsh name to the 
rocks in the face of which the true "twll ddu" opens. Mr. W. Wilson 
has remarked that the leaves of S, decipiens are sometimes apparently 
pointed, but "that the point is not cartilaginous; as in S, /typnoides, 
but only a terminal jointed glandular hair, in every respect similar to 
those found on the margins of the lobes. He also tells ns that the 
common base of the leaves has five ribs in place of three ; also, the pe- 
tals are " 3-ribbed [that is, as I understand it, triple-ribbed] ; never 
furnished with lateral veins, as in many of the wild and most of the 
cultivated states of S. Jii/pnoides'' (Hook. Brit, Fl. ed. i. p. 196, or the 
corresponding page of the 2nd and 3rd editions, also in Bot. Miscell. iii. 
p. 110), I have not the materials for fox'ming an opinion on the petals 
of the British plants, but have the utmost confidence in Mr. W. Wilson's 
accuracy of observation. The S. incurvifoUa , as drawn by J. De C. 
Sowerby, has triple-veined petals, as also has S. affinls (judging from 
my specimens and the drawing). So also S. Iiirta, although incorrectly 
represented on the detached petal in * English Botany/ I cannot com- 
bine these plants with S, Iiypnoides^ as is done by Mr. SymCj for the 
above reason, in addition to those which I have formerly given: 
C. C. Babington. 
A GIGANTIC EQUISEIUM. 
r 
It will be remembered that a few years ago Dr. Spruce had the good 
fortune to meet, on the eastern slopes of the Andes, with a grove of 
gigantic Horsetails, some of which were more than 20 feet high, looked 
somewhat like larches, and forcibly reminded him of the extinct Cala- 
mites of b3^gone geological periods. I myself saw an Eqmsetiariy about 
] 2 feet highj in even so unfavourable a climate as that between Callao 
and Lima, and I am therefore somewhat prepared for the interesting 
discovery which my friend Mr. Ernst has just made in the neighbour- 
hood of Caracas, Yenezuela, He has found there an Eqfdseti^m, which, 
by actual measurement, proved to be 36 feet high, but scarcely | of 
K 2 
