278 
specimens in the Pirongia ranges, in the Upper Waikato, and Professor Hutton received it from the 
Mokau district. 
Its range may therefore be described as pretty general, although it is not very plentiful in any 
part of the country. It does not, however, occur out of New Zealand, nor has it any known ally. 
In the autumn of 1863, I visited the upper gorges of the Manawatu river, and obtained a fine 
series of specimens in the various states of plumage. The crops of those which I opened were filled 
with a species of caddis-worm ; ” and on turning out the contents I discovered the nest of this insect, 
consisting of a tough integument shielded by small angular stones firmly glued over the entire surface. 
The caddis-worms were of different sizes (none, however, exceeding an inch in length), light brown 
in colour, with a dark head armed with three nuchal plates, and furnished with six legs. This insect 
appears to exist abundantly in all our shingle-rivers, and as we may assume that it forms the chief, if 
not the only food of the Blue Duck, the troublesome task of dislodging the animal from its stone- 
covered cell appears to explain at once the use of the fleshy membrane which fringes the bill of this 
bird. That it is at any rate, an expert, may be inferred from the fact that out of several hundred 
specimens taken from the crops of my birds, only one of these insects was invested with the case or 
integument, this having probably been swallowed by accident among the rest. 
Several pairs of this Duck were kept for some months in the Acclimatization Gardens at Christ- 
church and became perfectly tame. They were ultimately shipped home to the Zoological Society. 
Mr. Potts states that on examining an embryo of three weeks he found the form of the bill well 
developed, showing on the sides, near the end of the upper mandible, the peculiar membranous 
appendage of a darker colour than the rest of the bill, but that he was unable to discern the presence 
of lamellae ; the caudal down was produced to a remarked degree. The same accurate observer has 
furnished the following interesting account of the breeding-habits of this species : — “ Sometimes it is 
a burrower, and its nest may then be found in a hole in a bank. I have found it concealed from 
view by overhanging sprays of those various Alpine veronicas which sometimes make the mountain- 
creeks in the back country perfect gems of beauty. Tbe nest, like that of other ducks, thickly lined 
with down, generally contains five eggs of a deep cream-colour, elliptical in form, measuring 2 inches 
81 lines in length, with a diameter of 1 inch 9 lines. I have seen nests of eggs in October and 
November, but I have known the young brood to be swimming about by the end of September. We 
may therefore consider it one of our early breeders. As I have mentioned that it breeds in holes of 
banks, it is worth recording, perhaps, that I have found the nest in situations that did not afford any 
great amount of shelter ; one such instance was met with on a spit in the Upper Ashburton river, 
about three miles below the glacier from which that river derives its source : the nest was placed in 
a solitary snow-grass tussock of moderate size, within two or three yards of the stream ; it was made 
of grasses, the interior composed of cut grass like chaff, down, and a few feathers.” 
Mr. Hill, school inspector, was up in the Kuahine ranges (Hawke’s Bay side) towards the end of 
November, and caught some young Wio there. They were very active in the water, diving per- 
sistently, and when hard pressed they took to the bank and endeavoured to secrete themselves. 
The old birds remained on the water within sight and made no sign ; but before the discovery of 
the young, they had tried to divert attention by feigning disability on the water, as if inviting pursuit. 
There are several specimens of the egg of this bird in the Canterbury Museum. They are 
narrower or more elliptical in form than those of most other Ducks, measuring 2-6 inches in length 
by 1-7 in breadth; they are of a pale cream-colour, slightly tinged with green, and some of them 
much stained on the surface, probably from contact with the bird’s feet during the process of 
incubation. 
