CnzrzsEMAN.— On new Opisthobranchiate Mollusca, 979 
microscopic white dots. Mantle smooth, not nearly so long as the foot, and 
not concealing the branchism, rather broader on the right side; oral veil 
broad, extending over and concealing the mouth, in front semicircular, and 
with a delicate fringed margin, but at each side produced into a short 
tentacle-like lobe; mouth large, round, in a state of rest concealed in the 
sulcus between the oral veil and the foot, but capable of being greatly pro- 
truded in a proboscidiform manner; buccal plates two, large, finely and 
regularly reticulated or faceted ; odontophore broad, with numerous rows of 
similar unciform teeth; tentacles dorsal, wide apart, short and stout, project- 
ing outwards, folded down the outer side, tips obliquely truncate; eyes 
minute, black, placed within the integument at the inner bases of the 
tentacles, quite internal, and not to be seen without dissection; foot long, 
extremely flexible, sole pale ashy grey; branchial plume often over an inch 
in length, and free for half that distance; pectinations about 17, finely 
ciliated; shell none; length 2:5 to 3:25 inches. 
This species is very abundant in Auckland Harbour, usually affecting 
sandy or muddy localities. In the winter and spring months large numbers 
are often exposed at neap tides, having probably come into shallow water to 
deposit their ova. Captain Hutton, of the Otago Museum, informs me that 
he has collected the same species at Port Nicholson. It is hardy and not 
easily killed, and may be kept in confinement for a long time. When in a 
healthy state it is by no means inactive, crawling along by means of its 
muscular foot much more quickly than might be expected. It has a curious 
habit of floating in a reversed position, just under the surface of the water; 
and I have also observed it swimming by means of rather violent vertical 
undulations of its body. 
8. AcrESIA GLAUCA, n. sp. (Plate XVL., fig. 4.) 
Body from 8 to 5 inches long, about ovate when at rest, but capable of 
considerable extension, a little contracted behind the head, then elevated, 
and suddenly sloping to a point posteriorly ; entirely covered with numerous 
simple and branched tentacle-like processes, the largest of which are some- 
times eight lines long. Colour on the sides pale greyish-brown, passing on 
the back into a dull sea-green; the whole surface with numerous irregularly 
shaped black blotehes that are largest on the back. Along the back there 
is also a double row of from 8 to 12 emerald-green specks, each surrounded 
with a zone of umber. Dorsal tentacles 3 inch long, folded down the outer 
side so as to appear tubular, beset with filiform appendages. Labial ten- 
tacles similar in shape, but rather larger. Branchial cavity large, protected 
by the folded-in edges of the mantle, branchiz quite internal; foot long and 
narrow, pointed behind, without side-lobes as in Aplysia, sole pale sea- 
green; mouth roundish, placed under the head; odontophore with very 
