1875.] MR. A. H. GARROD ON HALMATURUS LUCTUOSUS. 57 
form of a formula. Employing the divisions, so evidently natural, 
proposed by Prof. Flower, 1 commence by writing down the name 
of the largest lobe, after which the others in the order of their bulk, 
with symbols between each to indicate their relative size. Taking 
the liver-formula of Dorcopsis luctuosa as an example, it may be thus 
written, 
Li 2>G,. ->h:C, 5>Sp >8.L. 2>1L.C. ; 
and it reads as follows: —The left lateral lobe (L.L.) is the largest ; 
it is twice the size of the caudate (C.), which is half as large again 
as the right central (R.C.), which is half as large again as the Spi- 
gelian (Sp.), which is larger (very little) than the right lateral 
(R.L.), which is twice the size of the left central (L.C.). 
The similarly constructed formula of Macropus melanops is 
L.L.=C.2>R.C. $>R.L. $>Sp. 3>L.C., 
and of Halmaturus derbianus 
L.L. 13 >C=R.C. $>Sp. ¢>R.L. 2>L.C. : 
they show how great a similarity there is between the different mem- 
bers of the family Macropide. 
The gall-bladder is situated in the deep cystic fossa; and the um- 
bilical fissure is not deep. The Spigelian lobe has its apex directed 
vertebrally and resting on the left lateral lobe, as in Macropus ; no 
secondary lobules are connected with it. 
There is a peculiarity in the liver of the specimen of Dorcopsis luc- 
tuosa under consideration, which may be individual, or it may be 
characteristic of the species, genus, or subfamily; at all events, I 
have not seen itin any other mammalian animal. Looking at the 
diaphragmatic surface of any multilobate liver, the lateral margins of 
the mass formed by the right and left central lobes are always seen 
to overlap, toa greater or less extent, the lateral lobes in an imbricate 
manner. Similarly the right lateral lobe overlaps or covers the caudate. 
In the livers of Macropus and Halmaturus which I have by me, 
this conformation is strictly maintained. But in Dorcopsis luctuosa 
the caudate lobe overlaps the right lateral lobe (instead of being 
situated on its abdominal surface), in such a way that the last-named 
lobe is only seen between the right free edge of the right central 
lobe and the left free edge of the caudate. This condition is not 
brought about by any post mortem change in the position of the 
lobes, because the right lateral fissure is not so deep as to separate 
them at their vertebral extremity. 
The uterus is perfectly Macropine, as are the vaginee. No direct 
communication could be found between the uterine pouch of the 
vaginze and the common vaginal canal. 
A gland, as usual, about the size of an almond, with a slender 
duct, opens on each side of the narrow cavity included between the 
sphincter ani and the external common sphincter. 
In conclusion, the comparison of the various organs and structures 
