622 MR. P. CHALMERS MITCHELL ON THE [June 16, 
muscle, which spreads anteriorly and posteriorly over the lower 
surface of the space between the jaws, reaching forwards nearly to 
the posterior border of the mylohyoid anterior, and meeting its 
fellow from the other side in the middle line. The anterior or 
deeper division of the mylohyoid posterior has its origin partly in 
Fig. 2. 
Y 
Vijh 
Yh 
Dissection of hyoidean muscles of Opisthocomus cristatus. 
1, Geniohyoid, posterior division. 2. Geniohyoid, anterior division. 3. Mylo- 
hyoid anterior. 4. Mylohyoid posterior, posterior division. 5. Mylohyoid 
posterior, anterior division, 6, Ceratoglossus. 7. Ceratohyoid. 8. Depressor 
mandibule, G/., Mandibular gland. 
common with the foregoing division, but also extending a consider- 
able distance over the inner surface of the ramus, a condition that 
I have not found in any other bird. In the Pheasants the origin 
is normal, a narrow nearly yertical line in front of the depressor 
mandibule attachment. 
