MISCELLANEOUS NOTES. 



587 



No. III.— CCRIOUS COURSE TAKEN BY THE HYOID CORNUA OR 

 TONGUE MUSCLES IN CERTAIN WOODPECKERS. 



All woodpeckera are, as is well known, provided with excessively long, 

 worm-like tongues which enable them to extricate their food in the shape of 

 insect larvae, &c., from deep holes and crevices in the wood. 



To render the protrusion and subsequent withdrawal of such a long 

 tongue possible, specially constituted and exceedingly long hyoid cornua 

 or muscles which work the long tongue are necessary which, as a rule, in the 

 woodpeckers, slide round the skull from the sides of the gullet round the 

 occiput to the base of the upper mandible. 



This in itself is a strange course for the hyoids to take, but in the case of 

 two genera of woodpeckers, which I have recently examined, there exists a 

 much more extraordinary arrangement of these muscles which I cannot find 

 described and which has possibly not been recorded. 



The course taken by the hyoids in these two genera lies at first, in the 

 ordinary manner arourd the occiput, after which instead of passing straight 

 to near the base of the upper mandible, they turn to one side and make a 

 complete circuit of the eye socket, side by side. 



The above extraordinary arrangement of the hyoids is found in Pyrrlwpicus 

 pyrrhotus and in Picumnus innominatus. In both these species the hyoids 

 pass completely round one and the same eye (the right in both cases) as 

 shown in the accompanying diagrams : — 



Side elevation. 



Plan, 



Head of Fyrrhoplcus pyrrhotiis, showing course of hyoid cornua {dotted Lines), 



