Hurron.—On Anas gracilis, Buller. 271 
The coarse striations and shape of the shell of 4. venosa leave no doubt 
that my specimens differ from that animal. 
All my specimens discharged the purple fluid (which is characteristic of 
the genus) on being placed in fresh water, or otherwise annoyed. I noticed 
also that the lower lobes, which some authors say are used in swimming by 
this genus, are only used in that way by this species in a very qualified 
sense. They attach themselves to a rock or to sea-weed by their tail, and 
allow their body to drift about, simply guiding the direction of their body, 
and maintaining their upright position, by the movement of the lobes. 
As in Parmophorus, Bulla and Haliotis the shells of younger individuals 
were much larger in relation to their bodies than those of mature age. 
The two species, 4. brunnea and A. venosa, are, as far as I am aware, 
the only species of this family recorded in New Zealand; Capt. Hutton, in 
his “ List of the Marine Mollusca of New Zealand," mentions a single shell 
from the Bay of Islands. The habitats given for his two species are Wel- 
lington and Dunedin. 
The occurrence of this Molluse in this Province is therefore worth re- 
cording, even if it should prove to belong to one of those two species. If as 
I think, it is new, it requires to be put on record. I have, however, not had 
the advantage of seeing specimens of either of the above-mentioned species, 
so that I cannot definitely state the fact that it is new. 
Should it be so, I suggest that it should receive the name Aplysia tryonii, 
as a gentleman of the name of Tryon discovered it here, where I have (I 
trust not unobservantly in matters connected with conchology) lived for 
11 years without having observed it. 
Art. XXX.—On Anas gracilis, Buller. 
By Professor Hurron, of the Otago University. 
[Read before the Otago Institute, 14th October, 1879.] 
Tue Otago Museum has lately received from Paris a specimen of Quer- 
quedula gibberifrons, Miiller, from Celebes, and on comparing it with a 
specimen of Anas gracilis, Buller, from Otago, I find so many points of 
difference that I am compelled to call in question Dr. Finsch’s identification 
of the two birds. 
In Q. gibberifrons the breadth of the bill at its base is equal to its height; 
while in A. gracilis it is higher than broad at the base. In Q. gibberifrons 
the wing is shorter, and the middle toe is longer than in A. gracilis. 
There are also the following differences in colour: in Q. gibberifrons the 
