I12 GLOSSARY. 
Radial sesamoid.— The tubercle of the human 
scaphoid. Supposed by some to represent 
the first digit of the heptadactylus manus, 
7.é., a pre-pollex. 
Radius (L. vadzus, a ray, or spike).—The outer bone of 
the fore-arm. 
Ramus (L. ramus, a branch).—Each half of the lower 
jaw or mandible of the Vertebrata. 
Rostrum (L. vostrum, a bill or beak)—Applied to the 
anterior or facial portion of the skull of 
certain fishes, where greatly produced. A 
sharp prominence or spine in the middle 
line of the sphenoid bone of the skull. 
Sacral (L. sacrum, sacred).—Relating to the region of 
the sacrum. 
Sacrum.—The terminal anchylosed vertebrz, imme- 
diately succeeding the lumbar vertebre, to 
which the pelvic arch is articulated. 
Sagittal suture (L. sagz¢fa, an arrow ; sutura,a seam). 
—The suture uniting the parietal bones of 
the skull. 
Seaphoid (Gr. scaphe, a boat ; ezdos, shape).—Boat- 
shaped. 
Scaphoides (Gr. scaphe, a boat ; ezdos, shape).—One of 
the bones of the carpus, and also one of the 
tarsus. 
Scapho-lunar (Gr. scaphe, a boat ; L. /unar, a moon).— 
Seapula (L. the shoulder-blade).—The shoulder-blade 
of the pectoral arch of Vertebrata. 
Scapula accessoria (L. additional scapula).—A small 
