422 TRANSACTIONS OF SECTION D. 
in the intestine, the beginning of the latter only indicated by the entrance of the 
bile-duct. A gall-bladder on the lower face of the right liver-lobe. Behind the 
entrance of the bile-duct the intestine turns to the left side; after two convo- 
lutions below the left liver-lobe it runs transversely under the liver-bridge to 
the right side, and after two narrow convolutions it reaches the middle line and 
as the colon passes over the pelvis to the anus.—The kidneys are remarkably 
short, reaching from the skull over only one-third of the body cavity; urinary 
ducts long, urinary vesicle large, bilobed. Ovaries closed sacs behind the 
kidneys, oviducts short and wide. JZ'estes short and narrow. The caudal vein 
divides into two large veins passing along the urinary ducts into the kidneys. 
The aorta follows in the trunk the right side of the vertebre, giving off the 
arteria cceliaca far in front, just behind the union of the branchial arteriz 
revehentes, 
The facts mentioned above clearly show the Pegasus (1) to be an 
Acanthopterygian, (2) to represent at least a ‘suborder’ of its own, distin- 
guished by several structural peculiarities from all fishes hitherto known (see, 
for example, the quite unique precranial position of the pterygo-palatine bar 
together with the premaxilla and maxilla, the connection of the latter bones by 
means of an interpolated bone, &c.). Possibly the Pegaside (Hypostomides) 
may be a strongly modified offshoot trom the stem of the Scleroparei; but no 
existing mail-cheeked fish shows any closer relationship with the Pegasidw, 
certainly not forms like Agonus or Aspidophoroides. 
7. Acquired Habils of Muscidae (Sheep-Maggol-Flies). 
By Wauter W. Froaeatt, F.L.S. 
At the present time the most serious enemies of the land-owners and 
squatters in the greater part of pastoral Australia are several species of blow- 
flies. Forsaking their natural food, chiefly carrion, they have acquired the 
habit of blowing any soiled or damp wool on otherwise healthy sheep. 
All the flies in question, though well-known indigenous species common to 
the greater part of Australia, only learnt the value of soiled wool as a suitable 
place to deposit their eggs, or living maggots, within the last ten or twelve years, 
Previously they were known merely as ‘ blow-flies.’ Several kinds came into 
the house and dropped their eggs upon meat, or at times infested open wounds; 
but otherwise they were simply scavengers. Others were found about decaying 
animal matter in the vicinity of killing yards or butchers’ shops, a few feasted 
upon rotten fruit and such like fermenting vegetable matter. At the present 
time (1914) at least four species have been bred in, and identified from, soiled 
wool taken from sheep running in the paddocks under exactly the same con- 
ditions that have prevailed in sheep breeding in Australia for the last twenty- 
five years. 
Though this wool-blowing habit was unknown in this country until about 
twelve years ago, it is remarkable that in Great Britain, from a very early date 
in the records of sheep husbandry, two species of ‘ blue-bottles’ or ‘ blow-flies ’ 
have been known to do a certain amount of damage in exactly the same manner 
to the shepherd’s flocks. Though cosmopolitan in its range, Lucilia sericata, 
the common sheep-fly of Great Britain, has never been recorded as having affected 
healthy sheep in any other part of the world, except in one isolated case, when it 
was accidentally introduced with sheep into Holland. Prior to 1903 there may 
have been occasional cases of blown wool, under exceptional circumstances, as 
has been claimed by sheep-owners, when discussing the question of sheep- 
maggot-flies, but it was certainly a comparatively rare occurrence to find putrid 
blown wool. About the end of 1902 the writer first obtained samples of shorn 
wool containing living maggots; and in the following season they were reported 
doing considerable damage. Specimens were received for identification from 
the owners of flocks in the north, north-west, and from a large area of the 
southern plains. 
At first the point of infestation was round the tail where the wool had been 
soiled with the urine, and the injury was chiefly confined to close-woolled stud 
ewes. Within a very short time, however, the flies found that other kinds of 
