Messrs. Alder and Hancock on Nudibranchiate Mollusca. 311 
and at first green, but finally brown; they are large compared 
with the size of the plant, and are arranged in a circle near the 
margin. 
I am indebted to Dr. Dickie for determining the name of this 
plant, which I had supposed was one hitherto undescribed, and 
also for a specimen gathered at Falaise which he had received 
from M. Lenormand. 
Haying sent a British specimen to Professor Kiitzing, he in- 
formed me, that as far as he could determine from the dried 
specimen, it is his Phylactidium pulchellum; but although he 
considers it distinct from Coleochete scutata, which he has also 
gathered in Prussia, I believe that he has only described its 
young state as Phylactidium pulchellum, for his figure well repre- 
sents our plant before the appearance of bristles ; and as it is un- 
doubtedly Brébisson’s plant, I have retained the present name*. 
Piare X. fig. 2. Coleochete scutata: b, portion of a frond in fructifica- 
tion ; ¢, portion magnified to show the processes. 
XXXIV.—WNotice of a new genus and several new species of 
Nudibranchiate Mollusca. By JosuHua AutpER and ALBANY 
Hancock, Esqrs. 
Genus EumMENIs. 
Bopy elongated, quadrilateral ; head subinferior, with corneous 
jaws ; veil very small or none. Tentacles two, dorsal, clavate and 
laminated, with sheaths. Branchiz papillose, set on a waved 
pallial expansion down the sides of the back. Foot lear. Ori- 
fices of the generative organs and of the anus? on the right side. 
Eumenis marmorata. Body nearly linear, tapering to an ob- 
tuse pot behind; olive-brown, streaked and spotted with dark 
chocolate-brown and white. Head with a few tubercular pro- 
cesses in front. Tentacles clavate, broadly laminated on the 
upper part and truncated at the apex; lower part plain, inclosed 
in small and rather tight sheaths. The sides of the body are pro- 
duced into a pallial expansion, which undulates into three or four 
lobes, the margin set with irregular papillose branchiz of a fawn- 
colour with pale edges. Interrupted dark brown markings run 
down the centre of the back, streaked and spotted on each side 
with brown and white. The sides of the body below the margin 
of the cloak are also streaked with interrupted lines of dark brown 
* « Phylactidium, Kiitz. Phylloma minutum, monostromaticum, orbicu- 
lare,s. flabellatim conjuncta constituentibus compositum, Spermatia ignota.” 
—Kiitz, Phycologia Generalis, p. 294. 
“1. P. pulchellum, Kiitz. Orbiculare, ameene viride ; cellulis ezelogoni- 
micis, demum transverse zonatis, centro globulo gonimico majori notatis,” 
—Kiilz. l.c. p. 295. t. 16. f. 11. 
