202 SKELETON OF THE DOG 
BONES OF THE PELVIC LIMB 
The ilium is nearly parallel with the median plane and its axis is only slightly 
oblique with regard to the horizontal plane. The gluteal surface is concave. The 
pelvic surface is almost flat. The auricular surface faces almost directly inward, 
and in front of it there is an extensive rough area. The ilio-pectineal line is very 
distinct and is uninterrupted. The crest is strongly convex, thick, and rough. 
The tuber sacrale is represented by a thickened part which bears two eminences, 
homologous with the posterior superior and posterior inferior iliac spines of man. 
The tuber coxe also has two prominences, which are equivalent to the two anterior 
spines present in man. The shaft is almost sagittal and is compressed laterally. 
It is smooth and rounded dorsally, and it bears a ventro-lateral crest (Linea glu- 
te ventralis), which terminates at a tuberosity in front of the acetabulum. 
The ischium has a twisted appearance, owing to the fact that its acetabular 
part is nearly sagittal while the posterior part is almost horizontal. The two bones 
Fic. 222.—Ricur Os Cox or Doc; Laterat View. 
1, Gluteal surface of ilium; 2, crest of illum; 3, tuber sacrale; 4, tuber cox; 5, shaft of ilium; 6, nutrient fora- 
men; 7, greater sciatic notch; 8, ventral gluteal line; 9, tubercle to which rectus femoris is attached; 10, ilio-pectineal 
eminence; 11, 11’, acetabular and symphyseal branches of pubis; 12, articular surface of acetabulum; 12’, fossa acetab- 
uli; 13, obturator foramen; 14, ischiatie spine; 15, lesser sciatic notch; 16, 16’, acetabular and symphyseal branches 
of ischium; 17, tuber ischii. 
also diverge behind and the tubera are flattened and everted. The superior ischiatie 
spine is low and thick; its posterior part is marked by transverse grooves and has a 
prominent outer lip, The greater sciatic notch is elongated and very shallow. There 
is no lesser sciatic notch. The ischial arch is relatively small and is semi-elliptical. 
The symphyseal part of the pubis is thick and fuses late with the opposite bone. 
There is no subpubie groove. 
The acetabulum is about twice as far from the tuber cox as from the tuber 
ischii. The fossa acetabuli is deep, and is bounded medially by a flat plate of bone; 
its floor is so thin as to be translucent. There is a small notch behind. 
The obturator foramen resembles in outline an equilateral triangle with the 
angles rounded off. 
Union of the three parts of the os cox has usually taken place at six months, 
but the epiphyses of the ilium and ischium do not fuse with the main part of these 
bones till about the end of the second year. 
The inlet of the pelvis is very oblique. It is almost circular in the female, 
but in the male it is elliptical and the conjugate diameter is the longer. The cavity 
is narrowest between the acetabula, and very wide behind. The floor is concave 
and relatively narrow in front, wide and flat behind. 
