Farn: 3. PI. 40.
HERMÆA DENDRITICA.
HERMÆA DENDRITICA, Alder and Hancock.
H ovato-oblonga, postice attenuata, virescenti-alba, lineis vindibus dendriticis ornata: braucbiis
elliptico-linearibus, viridibus, in seriebns 8 digestis: tentacuiis wdidis, auriformibus: lateribus ante-
rioribus pedis subangulato-rotundatis.
Cattiopeea dendritica, Aid. and Hanc., in Ann. Nat. Hist., v. 12, p. 233^
Hob. On Codium tomentosum, near low-water mark, Torbay.
Body three tenths of an inch long, greenish white, with dendritical green markings.
It,is rather narrow behind the head, expanding towards the centre of the back and tapering
to a slender point at the tail, hut all the parts are capable of great elongation and contraction,
and are sometimes very much attenuated. The sides of the body are depressed, and generally
overhang the foot. Head rounded in front, with a sub-velar margin curved inwards in the
centre towards the mouth. Tentacles rather large, auriform, arising from the sides of the
head, and folded longitudinally; they are somewhat dilated at the base, and slightly tapering
and rounded at the apex, towards which there are a few opake white spots: a line of green
runs up the hack of each, which is branched at the sides. These lines unite with two principal
. dorsal lines, which pass "along the sides of the back, and terminate near the tail; in front, the
latter divide into many branches over the head, and in their course backwards give off lateral
branches proceeding to the branchiae, and covering the sides with beautiful and delicate
ramifications. Other branches pass in various directions from the main trunks ; the whole
exhibiting a granular structure. Brancliia long, and nearly linear when hilly extended,
tapering gradually at the top, elliptic oblong when contracted; the central vessel green and
lobated, giving them a transversely banded appearance : the outer sheath transparent, and
sprinkled over with opake white spots. The papillae are set in eight transverse rows, of
three or four each. Foot transparent white, tinged with green, rounded in front, slightly
produced and obtuse at the sides. It is rather broad, with nearly parallel sides, but
much attenuated posteriorly to the tail, which is often held in a curved position, and is
frequently much elongated. Dendritical markings are seen through the skin in the posterior
part. Anus forming , a rather stout, conspicuous tube on the back, hefore. the heart, and
not far from the commencement of the branchise. The eyes are large, and situated a little
behind the tentacles.
The heart pulsates ninety-six times in a minute.
Nearly a hundred specimens of this beautiful and curious little creature were sent to us
by Mrs. Wyatt, from Torquay, in the summer of i843, having been found by her on an
insulated piece of rock left bare at low tides in Torbay, feeding upon Codium tomentosum.
Unfortunately all the specimens were dead when they reached us, and the whole of the