76 Annals of the Carnegie Museum. 



Barring its very much smaller size, the pelvis in Callithrix presents 

 essentially the same characters as the bone in Lasiopyga. It is, 

 however, proportionately shorter, the obturator foramen proportion- 

 ately larger, and more circular, thus causing the cotyloid notch to be 

 nearer to its margin, while the ischio-pubic surfaces, internal and 

 external, are fiat, and the tuberosity of the ischium is but very slightly 

 enlarged. From its external point to the anterior pubic angle, the 

 border of this pelvis is uniformly convexly curved and almost sharp> 

 The spine of the ischium is absent in Callithrix, and very rudimentary 

 in Lasiopyga. Mivart found this process prominent in Simia. 



The Femur. Apart from the matter of relative size, the femur in 

 Lasiopyga griseoviridis presents the same characters as are met with 

 in that bone in Lasiopyga callitrichiis ; in the former it has an extreme 

 length of 14.8 cm., and in the latter of 13.2 cm. In Callithrix jacchus 

 it is only 5.4 cm. long. 



In Lasiopyga the femoral head is smooth, hemispherical in form, and 

 presents a deep pit for the insertion of the Ugamentum teres. The 

 neck is as well marked as it is in Homo, but it does not make quite 

 as open an angle with the axis of the shaft, and the massive trochanter 

 major rises somewhat above both it and the head of the bone. The 

 digital fossa which it overshadows is deep and circumscribed, and on 

 the posterior surface leads by a groove almost to the summit of the very 

 prominent trochanter minor, which groove is bounded by a definite 

 trochanterian line, no "spiral line" as in man being found opposite it 

 on the anterior aspect. Strong and highly polished, the cylindrical 

 shaft of the femur is considerably curved between the extremities, the 

 curve being quite uniform with the convexity in front. 



The Imea aspera is fairly well seen, and a single nutrient foramen is 

 found on the posterior surface of the shaft at a point between its middle 

 and upper third. Distally, the bone is much enlarged, and in many 

 respects resembles this extremity in the femur of man. The lower 

 points of the condyles, however, are in the same plane, the internal 

 condyle being the lower in man. There is a deep intercondylar fossa 

 between the jutting, prominent condyles posteriorly. Each of these, 

 in this locality, is surmounted by a large sesamoid, which in each case 

 articulates with it at its summit. Similar sesamoids of relatively 

 similar proportions are found in the skeleton of Callithrix occupying 

 like positions. No authority at hand mentions these sesamoids, 

 certainly not Huxley, Mivart, or Flower, yet they are very conspicuous 



