CurrsemMan.—On Nudibranchiate Mollusca. 213 
A careful examination of the fish shows, however, that it must be 
classed as a true sea or salmon trout, although, as has been found invariably 
to be the case in Otago specimens, it presents a certain admixture of the 
characters of the many species into which the sea trouts from the various 
rivers in Europe have been subdivided. 
The specimen proves to be a female that has just spawned. For the 
length of twenty-five inches its weight, four pounds, is small, but it is 
evidently lanky and out of condition, as otherwise it would have been a six 
pound fish. The stomach contained half-digested remains of a young 
barracouta (Thyrsites atun) and a sea mullet (Agonostoma forsteri), each 
about nine inches long, proving that it must have been feeding voraciously 
in salt water. The importance of this determination is due to the fact 
that the only salmon trout ever introduced to New Zealand were bred from 
a small lot of ova that came from Tasmania, in 1870, and of which the 
original stock, turned out in Shag River, Otago, did not exceed seventy or 
eighty fish. What are supposed to be the progeny of these now abound on 
the Otago coast, and this discovery might seem to point to its having 
spread in its migration round the coast as far as Blind Bay. On the other 
hand, it might be suggested that what we know as brown trout in the rivers 
are of the large fast-growing variety known as the Thames trout, but 
which, in New Zealand, enter the sea and acquire the characters of the true 
sea trout. 
Art. XXVIII.—On two Species of Nudibranchiate Mollusca. 
By T. F. Cuezseman, F.L.S, 
(Read before the Auckland Institute, 5th September, 1881.] 
Doris luctuosa, n.sp. 
Lenern 1-2 inches. Body oblong or linear-oblong, back peer 
rounded. Mantle small, rather narrow and hardly concealing the sides 
of the foot, smooth and soft to the touch, of a dirty filesh-brown more or less 
Spotted or streaked with reddish-brown; occasionally dirty white with a 
few reddish-brown markings. ‘Towards the sides of the mantle the reddish- 
rown markings are often arranged in more or less interrupted lines. 
Dorsal tentacles (rhinophores) stout, clavate, completely retractile within 
raised sheaths, strongly laminate, lamine over 20 in number. The lamine 
are blotched with dark purple and greenish-yellow, the tips of the eet 
are usually greenish-yellow. Branchie 5, rarely 6, forming an incom- 
Plete circle round the tubular anus, bipinnate or tiphanste, rounded at 
