398 
On the Sesamoids o f the Knee- Joint 
showing range of sizes from h io c and a. a is from Orang-vitan figured, h and c are from a second 
specimen, left and right joints respectively. No other sesamoids were found. 
Fig. 69 is a drawing of the same knee-joint as in Fig. 68 with the popliteal tendon containing the 
cyamella lateralis (cy.) turned back so as to disclose the facet ( /. for cy.) on which it articulates. 
Plate XXVII, Fig. 70 a and Fig. 70 6. Drawings from posterior and lateral aspects respectively of the 
left knee-joint of Lemur varia, showing the external (e.f.) and internal (/./.) fabellae, the cyamella (cy.) 
and an anterior external lunula (a.e.lu.) in position. The cyamella is seen in close relation to the head 
oi-the fibula and one notes how with flexed limb the external /<i6eHa will come into contact with it. 
Fig. 71 a. Drawing of posterior aspect of right knee-joint of Mycetis palUatus, showing internal 
fahella (i.f.), external fabella {e.f.) and cyamella (cy.). 
Fig. 71 b. Sesamoids from the joint in Fig. 71fl. a is posterior aspect, b anterior aspect of cyamella, 
c and d are res-peciively fabella mesialis, &nd fabella lateralis in posterior aspects. 
Fig. 72. Drawing of distal extremity of right femur of a Gibbon (Hylobates lar) which possessed only 
an internal sesamoid (i.f.) and no ossification in the popliteal tendon (p.t.) which was "horny " but not 
ossified. 
Fig. 73. Drawing of postero-lateral aspect of left knee-joint of Lemur mclanocephalus showing 
external (e.f.) and internal (/./.) fuhellae, the cyamella (cy.) enclosed in popliteal tendon, and an anterior 
external lunula. 
Plate XXVIII, Fig. 74 a. Drawing of posterior aspect of left knee-joint of Chiromys, the Aye-Aye. 
The two branches of M. gastrocnemius (qi and g^) have been deflected to show the external (e.f.) and the 
internal (i.f.) fabellae lying beneath ; below is the popliteal tendon (p.t.) with the cyamella lying on the 
head of the fibula ( fib.li.) and articulating with the tibia, po. is the popliteal muscle. 
Fig. 74 b. Drawing of the lateral aspect of the left knee-joint of Chiromys after Owen (Trans. Zool. 
Soc. London, Vol. v, 1866, Plate XIX) to indicate how in flexure of the knee the external fabella (e.f.) 
comes in contact with the cyamella [cy.). 
Fig. 75. Drawing in posterior aspect of left knee-joint of Lemur catta, showing external (e.f.) and 
internal (i.f.) fabellae, the cyamella (cy.) and an anterior external lunula (a.e.lu.). 
Fig. 76. Drawing of the lateral aspect of the left knee-joint of a dry specimen of Perodicticus potto, 
Bosman's Potto, showing the position of the anterior external lunula (a.e.lu.) and the cyamella (cy.) on 
the head of the fibula. The popliteal tendon sends a branch down to the head of the fibula (see our 
p. 378). The fabellae had disappeared from this specimen, but it is clear that, in this flexed position of 
the limb, the lateral fabella must rest on the proximal surface of the cyamella. 
Fig. 77. Drawing of the lateral aspect of the left knee-joint of Indris brevicaudata, the Indri, showing 
the popliteal tendon (p.t.) containing the cyamella (cy.) and the positions of external (e.f.) and internal (i.f.) 
fabellae. The intimate relations of external fabella and cyamella on complete flexure are again indicated. 
Plate XXIX, Fig. 78. Eight, photograph of right pelvic limb of Phascolomys luombatus, the Wombat. 
This specimen shows the parafibula absolutely fused to the fibula so as to show one continuous bone 
with very small indication of position of union. 
Left, photograph of right pelvic limb of Sarcophilus tirsinus, the Tasmanian Devil; the parafibula is 
united to the fibula, but its limits are more clearly defined. 
Fig. 79. Photograph of left pelvic limb of Wombat, the two portions of the parafibula, which is really 
free of the fibula, are shown in position on the head of the fibula, the femur is tied back to show up the 
parafibula which in the usual flexed position would be in contact or almost in contact with the shaft of 
the femur. 
Plate XXX, Fig. 80. Photograph of the left pelvic limb of Phalangista valpina, the Wolflne Phalanger, 
showing the free parafibula (paraf.) mounted on the head of the fibula and its relation to the femur when 
the limb is flexed. The two portions of the parafibula, which ultimately become the lateral fabella and 
the cyamella, are easily distinguished. 
Plate XXXI, Fig. 81. Drawing of the posterior aspect of the right knee-joint of the Wombat with 
muscles attached. Description chiefly on figure itself. The external gastrocnemius has been cut across 
and the proximal portion deflected to show parafibular sesamoid lying in its fibres, and the surface of the 
fibula with which the sesamoid articulates. The internal gastrocnemius takes origin from nearly the 
