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n 22 DR. J. MURIE ON THE THREE-B/VNDED ARMADILLO 



Felvic admeasurements. 



inches. 



175 



Length from anterior spinous process of ilium to tuberosity of ischium in a straight line . 3'6 



Length from anterior spinous process of ilium to obturator edge of acetabulum ... 2-0 



Length from ilio-pectineal eminence (=mid-acetabulum) to outer pubo-ischial tuberosity 1-3 



Greatest vertical depth, viz. a line from sacral spine to symphysis pubis 2-0 



Narrowest exterior diameter, viz. behind anterior iliac processes (which are a trifle wider) . 0-85 



Widest outward diameter, at front edge, rim of the acetabulum 



Width from spine to spine adjoining the lesser sciatic-foramen notches I.45 



Diameter taken across the tuberosities of the ischium I.75 



Vertical or conjugate diameter of the brim of the pelvis 1-7 



Transverse diameter of same , .TO 



The obhque diameter (sacro-iliac synchondrosis to opposite outer pubic brim) .... 1-6 



From the pubis to the spine of posterior ischio-pubic outlet .1-4 



The inner or ischial diameter of the same 1-45 



r 



Greatest oblique diameter of posterior pelvic outlet . , ' . . . . 1"5 



otlu 



The outline of the brim of pelvis is somewliat egg-shaped, the symphysial being rather 



wider than the sacral end. The posterior or ischio-pubic outlet, a segment of an oval 



in figure, is considerably wider and shorter. The slender symphysis pubis is a wide low 



bridge of bone, with distinct centres of ossification from the outspread descending limbs 



of the arch. Another point I may as lief note is the presence of a double tuberculous 



(dcvation {sp, fig. 35) immediately adjoining what represents an abortive lesser sciatic 

 notch. 



The strong flat and broad first ribs are so firmly fastened to the manubrium as almost 

 to restrict tliis costo-sternal arch to short antero-posterior movement during the 

 rcspirafory act. There is not al^solute anchylosis, as M. Nodot ^ and subsequent writers 

 affirni is the case in Glyptodon ; but it is possible that, as age advances, a true bony 



II may also result iiiTolypeutes. Withal it is but a grade of solidification; for 

 nvise, as concerns respiration &c., the functional effects must have a certain 

 identity. The 2nd rib has a long ossided costal cartilage (sternal rib), which arti- 

 culates laterally with the manubrium. The succeeding four ribs, with increased and wide 

 arching, possess proportionally very lengthened sternal appendices. These latter are 

 ahnost entirely true bone, the semicartilaginous part being that attached to the ribs 

 and by a synovial joint, as Parker^ has shown in Tatima, Xenurus, and Dasyfus. 

 Durmg the rolUng-up action of the body the six anterior (true) ribs and inner segments 

 have a tendency to be huddled together and override. As a provision, the sternal pieces 

 are widest outwards ; and between each other there exists an articular facet. The 

 sternal appendix of the 7th (foremost false) rib is united by bone inwardly to the 6tL 



i he last (11th) nb is longer than the 1st, and distinguished from it and the 2nd by being 

 sti-aighter. ° 



Each piece of the hreast-bone has an interest attached to it; and as a chain of bones 

 their construction is admh-ably adapted to the modified positions which the animal 



iCay boc. Monog. 1868, Shoulder-girdle and sternum," p. 205, dL xxiii. 



