Vol. XII. 



1913 



1 Shufeldt, Osteology of Cereopsis novcv-hollandtcs. 233 



pressed from side to side, tapers gradually, though rather smartly, 

 to the end of the " fibular ridge " upon which it articulates with 

 the tibio-tarsus, after which it becomes very small and slender, 

 and co-ossifies with the side of its companion-bone of the leg, at 

 the commencement of its lower third. 



The characters, as above described, of these two bones of the 

 pelvic limb are repeated with but slight differences in the corre- 

 sponding ones of Chen hyperboreus nivalis, and probably other 

 anserines. 



With an extreme length of 104 millimetres, the tar so -metatarsus 

 of this Cape Barren Goose is proportionately as strong and as 

 straight as the other long bones of this limb. 



At its summit, the depressions to receive the articulation of 

 the condyles of the tibio-tarsus are deep and well separated, and 

 especially by the prominent intercondylar tubercle, which, as a 

 rounded elevation, surmounts, at the middle line, the anterior 

 border just above the deep concavity at the head of the shaft 

 of the bone on that aspect. 



At the base of this concavity are to be noted the two small 

 foramina, placed side by side, which pass antero-posterioiiy 

 through the bone — one to emerge on the internal face of the 

 hypotarsus, and the other passing through it. Below these, 

 anteriorly, we are to observe the small parallel elongate tubercles 

 for the insertion of the tendon of the tibialis anticus muscle 

 (" Myology of the Raven," p. 201, fig. 55). 



As to the shaft, it is for the most part flat and smooth in front 

 — that is, below the longitudinal groove traversing its upper half, 

 which latter shades away at its middle third. Dis tally, it is 

 expanded on account of the trochlefe. 



Posteriorly, we have above, at its distal end, the hypotarsus, 

 which is here very broad, rather deep anteriorly, more particularly 

 so on the mesial side where its hinder border is extended clear 

 down the entire length of the posterior aspect of the shaft, almost 

 to the inner trochlea. There are two other such " guides " to 

 the tendons, which, as fine raised lines, run down the back of the 

 shaft of this bone. 



Smooth and flat on its inner aspect, we are to note further, in 

 regard to the hypotarsus, that it has three longitudinal canals 

 for the passage of tendons on their way to the toes. External 

 to these canals, there is still another open groove, also for the 

 accommodation of a tendon. Probably the aforesaid canals do 

 not seal over with osseous tissue until the individual has fully 

 matured with respect to such changes. Prior to that time, these 

 canals are, posteriorly, backed only with fibrous tissue, which is 

 what ossifies later on in life. 



Branta has a tarso-metatarsus similar to that bone in Cereopsis, 

 but the tendinal groove to the outer side of the hypotarsus is not 

 quite as well defined. 



As to the posterior exits of the two foramina that perforate the 

 upper extremity of the shaft, one is found in plain sight at the 



