412- Annals of the Carnegie Museum. 



twenty-second vertebrce, these being the third and fourth segments ap- 

 j)ro|)riated l)y the sacrum. 



Now, in my male specimen of the paroquet, I find that the nine- 

 teenth to the twenty-ninth vertebras, inchisive, form the pelvic sacrum, 

 while in the female an additional segment, which in the male remains 

 a free caudal, has become firmly attached behind. 



This circumstance gives the male six free tail vertebra;, whereas the 

 other specimen has but five. Such a condition as this, however, not un- 

 frequently happens among birds, where the count for the entire number 

 of vertebra; in the column remains wonderfully constant for the species. 



The caudal vertebrae (PI. I, Fig. 2) have spreading transverse proc- 

 esses, and stumpy neural spines ; the ultimate two having strong bifid 

 hypapophyses. 



Of an irregular quadrilateral outline, the pygostyle has thickened 

 hinder and lower margins, while the remaining two are cultrate. 



Giving our attention now to the/c/z'/V, we find this compound bone 

 in Couitrus (PI. I, Fig. 2) devoid of any very striking features, it 

 having all the general characteristics of this part of the avian skeleton, 

 lacking anything to particularly distinguish it from the form the bone 

 usually assumes among most ordinary birds. 



Viewed from above, it will be seen that the pre- and postacetabular 

 areas are about equal in extent, the ilium being concave where it forms 

 the first, and the reverse where it constitutes the latter. For the entire 

 length of the .sacrum these bones are firmly sealed to its outer margins, 

 forming the most complete " ilio-neural canals" anteriorly, which do 

 not even open posteriorly as in some birds ; while behind it lends to 

 the postacetabular area a very unbroken aspect, that is rendered even 

 more so from the absence of all but a few small foramina among the 

 sacral diapoi)hyses. 



Upon the lateral aspect of the pelvis we note that the propubis is not 

 developed, and that the inner periphery of the cotyloid ring is nearly 

 as large as the outer one. The small obturator foramen is rendered 

 complete by a pretty thorough meeting between the ischium and the 

 somewhat .slender postpubis immediately behind it. 



The obturator space is long and si)indle-shaped, but the lower angle 

 of the ischium does not meet the ])Ostpubic shaft beneath it, as it does 

 in so many birds. 



The antitrochanter and the elliptical ischial foramen are both of 

 comparatively moderate size. 



