OCR Text |
Show 1895.] AND BEAIN OF DENDEOLAQUS BENNETTI. 135 Owen in D. inustus. In the species which forms the subject of present memoir, the liver formula may be represented on Garrod's plan thus:- L.L. 2>L.C.=R.C. 2>R.L. 3<Cau. This formula differs markedly from that of Petrogale penicillata, which is as follows :- L.L. 4>L.C.=R.C.<R.L. 3<Cau. I am not disposed to think that very much stress can always be laid upon the relative sizes of the lobes of the liver. For example, in two species of Halmaturus the formula? are as follows:- H. bennetti. L.L.<L.C. >R.C. 2>R.L. 3<Cau. H. brachyurus. L.L. 2 >L.C. = R.C. = R.L. 2 < Cau. (Garrod, MS. sketch). On the other hand, the liver of Dendrolagus shows two characters by which it can be distinguished from that of all the above-mentioned species and from Petrogale (fig. 4) and Macropus melanops -.- (1) The right lateral lobe is not separated by a complete fissure from the caudate. (2) The Spigelian lobe is distinctly bilobed. Fig. 4. Liver of Petrogcde; abdominal surface. Lettering as in fig. 3. § Heart and Vascular System. The only point that I noticed in the structure of the heart as compared with that of Petrogale is the presence of four separate papillary muscles attached to the free flap of the right auriculo-ventricular valve, instead of only three. The additional muscle was attached to the free wall of the ventricle. |