i:4S 



ME. G. P. MUDGE 0>^ THE MYOLOGY 



hidden ; in otiirrs the anterior part only is covered, and in yet others neither portion is 

 covered. 



Undoubtedly the most primitive condition of the muscle is that exhibited in 

 Utrmgops (PI. XXVI. fig. 2, mh.a.), Avhere it extends backwards to the posterior 

 portion of the inter-ramal area. Anteriorly, it arises in the way already indicated, 

 but posteriorly it arises on either side in the form of a narrow crescentic band of 



Test-fig. 10. 



Coimriis j<:nc7a?/n .—Yeutral view. On the left, half of the mandible has been removed, but otheiivise the 



parts are in situ. (Twice nat. size.) 



(jli.a. = geniohj'oideus anterior. 

 f/Zi.p. = ,, posterior. 



riJi.a. = mylohj-oideus anterior. 



hiJt.a^. = 



Additional letters. 



s.li. = sternohj'oideus. 

 se.h. = serpihyoideus. 

 st.h. = stylohyoideus. 



(posterior portion). 



muscular tissue, from the same origin as the serpihyoideus. It has undergone con- 

 siderable retrogression, for the whole of its middle third consists of nothing but the 

 persistent fascia of the muscle, and even in the middle line of the anterior third the 

 muscular fibre has disappeared. The posterior portion (mh.a^.) lies in the same 

 position that it occupies in other Parrots, but it is inserted to the connective-tissue 

 sheath that invests the urohyal, a cartilaginous nodule not being present. 



