624 H Y D 
wife of his intimate friend, Lepaute, a watch-maker. In 
Dtthamel’s recent work, Traite des Arbres, &c. it is-made 
a diflinet genus. It is a ihrub which rifes to two or three 
feet, fomewhat ligneous. Stems branchy, thick, cylin¬ 
drical, ftraight; branches furnilhed with oppofifte leaves. 
Leaf-ftalk, lhort, thick, of a whitilh-green, (lightly tile- 
channelled on the upper furface; leaves elliptical, large, 
from fix to nine inches long, fmooth on both fides, gloliy 
on the upper furface, tipped with a beautiful green, and 
fometimes with a purplifh red, marked by large fibres, 
which form an acute angle with the-mid-rib, and deeply 
ferrated on the edges. Flowers of a red colour, in a ter¬ 
minating corymbus. It is a native of China and Japan 
and it is only of late that the plant has been known in 
■Europe. It was formerly .cultivated at the Reduit, a gar¬ 
den in the Ifle of France, having been brought thither 
from China. In 1789, the date of the then catalogue, it 
had not found admiflion into the royal garden there. At 
prefent, it is very common in the environs of Paris, and in 
molt parts of France. Of the ornamental (lirubs which 
have been recently domefticated in France and England, 
few are more interelting than the hortenfia. Its beauti¬ 
ful blofloms of a rofy hue, and deltined to retain their 
gayeft afpedt during feveral months of fummer, entitle it 
to the attention of every fiorifl. Though deftitute of 
I'm ell, this (liowy plant has long been an objedt of parti¬ 
cular attention among the Chinese; for we find its blof- 
foms painted on molt of the Huffs and papers which we 
import from their country. 
Propagation and Culture. The firfl fort is eafilv increafed 
by parting the roots at the end of Odtober, which is alfo 
the .belt time to tranfplant them. It (liould have a moifl 
foil, for it grows naturally in marfhy places; and requires 
no other culture but to keep the plants clean from weeds, 
and to dig the ground between them every winter. If in 
feveral frofts the (talks are killed, they will put out new 
ones the following fpring. The fecond has not been in¬ 
troduced here. But the third, being very eafily increafed 
by cuttings, has been pretty generally diffufed within the 
compafs of a few years. The foil that it thrives bell in 
is a good rich loam. Some trials have been made with it 
to Hand abroad ; and it is hardy enough, in a (heltered 
fituation and warm foil, to endure mod of our winters; 
but it does not flower fo well in the open air as in a green- 
rioufe. It therefore mult be confidered rather as a green- 
houfe-plant than a hardy one; and fuperfluous plants 
■only ventured in the open borders of the flower-garden. 
H YDRACH'NA ,f The Water-Mite; in entomo¬ 
logy, a genus of apterous infefts; of which the generic 
characters are : Head, thorax, and abdomen, qnited or con¬ 
nate ; feelers two, jointed; eyes two, four, or fix; legs 
eight, formed for fwimming. The genus liydrachna, al¬ 
lied in the clofeH manner to that of aearus, under which 
the only fpecies known to Linnaeus were arranged, was 
nrfl inflituted by the ingenious Muller, by whole induf- 
trious refearches many new and curious kinds have been 
difcovered. They are inhabitants of Hagnant waters, and 
fwim with great velocity; they prey on the larvae of ti- 
pulae and monoculi. The eggs are red, and at firft fpheri- 
cal, but afterwards become lemilunar. The larva is fix¬ 
footed, and furnifhed with a very lingular probofcis. 
There are forty-nine fpecies, in five divifions. 
I. Eyes two; body tailed. 1. Hydrachna globator: 
body.globular, with red eyes. The male is greenifh (pot¬ 
ted ; the female bluifh, immaculate, and twice as large. 
This fpecies is found plentifully in Hagnant waters. 
z. Hydrachna tabulator: globular, yellowifh with a 
fpotted dilk; tail cylindrical, equal. Inhabits Hagnant 
waters. 
3. Hydrachna buccinator: obovate, red, and black be¬ 
hind ; tail cylindrical, yellow', and narrowed at the bafe. 
Body beneath black; eyes reddifh; legs black. Found 
jn banks of rivers. 
4.. Hydrachna cufpidator: brown ; truncate before and 
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mucronafce behind; tail deprefled, tw'o-toothed. Body de- 
prefied and broadiflt on the fore-part, behind narrowed, 
and armed with an erect triangular fpine; eyes black ; 
legs pale. Inhabits fifh-ponds. 
5. Hydrachna puHulator : gibbous, red ; tail deprefled, 
with obtufe angles.. Body fmooth, and generally covered 
with vorticelli. Inhabits grafly Hreams. 
_ 6. Hydrachna albator : rounded, grey, with a white 
dilk : tail deprefled, three-toothed. Inhabits fifn-ponds. 
7. Hydrachna maculator: rounded, cinereous, fpotted, 
and mucronate behind ; tail deprefled, three-toothed. 
Brealt whitifli; .legs green. , Found in ditches. 
8 . Hydrachna tricufpidator: red, with a triple gibbo- 
fitv on the back; tail deprefled, three-toothed. Body fub- 
reticulate.; breafl blackifh ; feelers and legs whitifh. In¬ 
habits’ pools. 
0. Hydrachna emarginator : red, with a gibbous back ; 
tail deprefled, emarginnte. Refembles H. puftulator. 
Feelers and legs greenifh. Inhabits bogs. 
10. Hydrachna finuator: grey; the back yellowifh on 
the Lore-part, and tri-punflured behind ; tail deprefled, 
finuate. Body reticulate ; feelers and legs white. Inha¬ 
bits Hagnant water. 
u. Hydrachna integrator: green, immaculate, with a 
deprefled, entire, tail. Body roundifh-oval, deprefled and 
contrabled behind ; breaH yellowifh ; legs hyaline. In¬ 
habits ditches. 
iz. Hydrachna papillator: rounded ; purple, with an 
excrelcence on each fide the tail; legs black. Inhabits 
wet meadows. 
11. Eyes two; back marked with a fork. 13. Hy¬ 
drachna craflipes: obovate; black, the dilk black, with a 
reddifh fork ; tail papillous; fore-legs thick. Body pel¬ 
lucid, with a white breaH; legs three or four times as long 
as the body. Inhabits ditches. 
14.. Hydrachna groflipes : nearly fquare; white, with 
three lpots, and a rufous fork; fore-legs thick. Body 
pellucid, glabrous ; legs twice as long as the body. In¬ 
habits fifh-ponds. 
15. Hydrachna clavicornis: obovate; rufous, with a 
yellow fork; feelers clavate; legs pale. Eyes black; 
feelers and legs white. Inhabits ponds. 
16. Hydrachna fpinipes: oval; greenifli-yellow, with 
eight dots and a rufous fork ; legs fpinous. Body po,- 
lifhed, with black eyes, breaH, legs, and dots on the back. 
Inhabits pools. 
17. Hydrachna lorigicornis: nearly fquare ; white, with 
five brown'fpots, and a rufous fork; feelers long. Inha¬ 
bits rivulets. 
18. Hydrachna vernalis: oval; greenifli, with a deeper 
dilk, and rufous fork. Has the appearance of a grey dot, 
with extended white legs. Inhabits overflowed meadow-s. 
19. Hydrachna lunipes: oval; wdiite, fpotted, with a 
clear white fork ; fourth joint of the hind legs lunate. 
Body pellucid, with large eyes; feelers and legs pale. 
Inhabits ditches. 
20. Hydrachna trifurcalis : oval; whitifli, with a brown 
back, and triple lilvery fork. Feelers ending in a claw, 
and with the legs pale greenifh-white; eyes black; ab¬ 
domen beneath, fometimes brown, with a wdiite line. In¬ 
habits wet meadows. 
21. Hydrachna orbicularis: deprefled; orbicular, pale 
yellow, with black fpots on the dilk, and a rufous fork 
Eyes black; legs white. Inhabits fords of rivers. 
22. Hydrachna flellaris : globular; blue, with a cine¬ 
reous back, and Hellate fork. Body reticulate; legs hard¬ 
ly longer than the body. Inhabits banks of rivulets. 
23. Hydrachna ovalis : ovate compreffed ; greenifh and 
flattifli above, carinate and yellow-browm beneath ; feelers 
placed beneath. Eyes and legs black ; feelers placed be¬ 
neath the legs. Inhabits overflowed meadows. 
24.. Hydrachna elliptica: rounded; blue, with fulvous 
Fpots and dots. Eyes black; legs wdiite; breafl, tail, and 
hind margin, yellowilh. Inhabits rivulets. 
25. Hydrachna 
