THE PHALANGEAL BONES 341 
ginis ot larger pastern, the next the os corona or lesser pastern, and the 
lowest the os pedis or coffin-bone. 
Tue Os Surrracinis and its Ossa SESAMOIDEA 
may be taken together, the latter lying on each side 
of the back of ils superior extremity, but playing 
only on the large metacarpal. They are separately 
shown at Fig. 30. The os suffraginis has a body 
and two extremities. 
THE BoDY shows an anterior surface, which is py¢, 39.—Ossa SusamorpEa. 
convex and smooth ; and a posterior which is rough 
and flattened, and presents superiorly a triangular space, bounded laterally 
by two roughened ridges, which meet at a point inferiorly. 
THE SUPERIOR EXTREMITY presents two shallow concavities, which are 
separated one from the other by a deep transverse canal. Behind these 
concavities, two tuberosities exist for the attachment of the crucial 
ligaments. 
THE INFERIOR EXTREMITY has two semi-cylindroid convexities, divided 
transversely by a shallow depression, which is widened posteriorly. 
Os Coron (corona, @ coronet) is in form a parallelogram with four 
surfaces. 
THE ANTERIOR SURFACE is convex and roughened, presenting two 
tuberosities below. 
THE POSTERIOR SURFACE is smooth, and has superiorly a semilunar 
smooth surface. 
THE SUPERIOR SURFACE presents two ovoid concavities, divided by an 
eminence running from behind forwards, and bounded, anteriorly and 
Fie. 31.—Postertor VIEW OF PHA- 
LANGES. 
A. Os suffraginis. 
1. 1. Surfaces articulating with the 
lower extremity of the large 
metacarpal bone. 
2. Groove. 
3. Rough surface for the implanta- 
tion of ligaments. 
4, 4. Inferior extremity articulat- 
ing with 
B. Os corone. 
5. 5. Superior articulatory surfaces. 
6. 6. Inferior articulatory surfaces. 
Cc. Os pedis. 
7. 7. Articulatory surfaces. 
8. 8. Coronal process. 
9. 9. Scutiform processes. 
10. 10. Retrossal processes. 
11. Surface articulating with a cor- 
responding one oz the navi- 
cular bone. (12.) 
D. Os naviculare. 
12. Surface articulating with the os 
corone. 
13. Surface over which the flexor 
pedis perforans tendon 
glides. 
fy 14 Points attached to the pedal 
bone by ligaments. 
