46 



THE AMERICAN NA TURALIST. [Vol. XXXVII. 



similar to the 'marsupial' bone of the implacental Mammalia 

 and its corresponding fibrous representative in certain Carniv- 

 ora." 1 As it has not yet received any special name it might 

 be called the suprapubic ossicle. In Garrod's figure, where it 

 is given, the pubis and ischium are firmly united posteriorly, 

 as is also the case in Owen's figure, cited above, while in the 

 pelvis of the ostrich in the collection of the United States 

 National Museum these bones are distinctly independent of 

 each other posteriorly (Fig. i). Perhaps these do not unite 

 until the bird is greatly advanced in age, and that this specimen 

 is in a subadult stage of growth, which is the more likely as 

 the epiphyses of the proximal extremities of the tarsometatar- 

 sals have not as yet coossified with the shaft. 



Owen 



'the ostrich the two clavicle 



from each other, but are severally anchylosed with the coracoid 

 and scapula, so as to form with them one bone on either side." 



In the pectoral extremity the humerus of the arm is reduced 

 to a mere curved and slender rod of bone, with slightly enlarged 

 ends ; while the radius and ulna of the antebrachium are even 

 more decidedly aborted. 



In The Ibis and in The Philosophical Transactions of the 

 Royal Society of London (1888) W. K. Parker has given 

 instructive figures of the manus of Struthio came/us, and they 

 go to show that in the adult individual the radiale and ulnare 

 ossicles of the carpus are separate and in bone. The phalanges 

 have a most reptilian look, and the terminal joints of all three 

 fingers are distally armed with a free, movable claw. 



The pelvic extremity of Struthio is powerfully developed, all 

 the bones present being massive and strong. Both the proxi- 

 mal end of the femur and its distal condyles are greatly 

 enlarged. A patella is not developed in bone. The tibio- 

 tarsus and tarsometatarsus are straight, and of nearly the same 

 length. The distal end of the latter is modified for the articu- 

 lation of the third and fourth digits, the only two toes possessed 

 by this bird. 



The cnemial process of the tibia is ossified by a separate 

 epiphysis, in common with Rhea. Owen says the pneumatic 



