238 MR. W. K. PARKER ON THE OSTEOLOGY 



EXPLANATION OF THE PLATES. 



PLATE XXXIV. 



Hemipodius ? sd. Sesamoid at angle of jaw. 



Fig. 1. Basal view of skull. q. Os quadratum. 



so. Superoccipital. qj. Quadrato-jugal. 

 m.o.f. Middle occipital fontanelle. j. Jugal. 



eo. Exoccipital. bs. Basisphenoid. 



o.c. Occipital condyle. pg. Pterygoid. 



bo. Basioccipital. pa. Palatine. 



9. Anterior and posterior condyloid ao. Antorbital. 



foramina. v. Vomer. 



8. Foramen for vagus nerve. pv. Prevomer. 

 i.e. Opening for internal carotid artery. n. Nasal. 



t.l. Anterior tympanic. px. Premaxillary. 

 t.2. Lateral tympanic. Fig. 2. End view of skull. 



bt. Basitemporal. ar. Articular. 



ornithic character is, that the cartilagiuous rings fail of perfection in two ways : firstly, in a few places they form 

 a short spiral with free ends ; and secondly, the lowest sis are open behind, as in the Mammalia. I do not find 

 this character in the Emus, the Mooruk (Casuarius Bennetii), the Rhea, or the Ostrich {Struthio camelus). 

 In the Emu, at the lower third the trachea is enlarged, and the rings are open in front at that part. In the 

 Tinamou the trachea is enlarged above the middle ; but the rings are complete in the dilated region. 



The Rhea has, unexpectedly, a pair of thick inferior laryngeal muscles ; I find none in the Mooruk, 

 Ostrich, Emu, or Tinamou : in this these birds agree with the typical and subtypical Fowls and the Geese. 



The Tinamou has the pharynx, crop, and gizzard exactly as in the true Gallinae ; but the proventricular glands 

 are not racemose as in the Fowl, the Grouse, the Rhea, and the Ostrich, but simple, as in the Pigeon, Sand- 

 grouse, Talegalla, Emu, and Cassowary. In these latter huge birds [Dromteus and Casuarius) the glandules 

 are long and cylindrical ; in the Tinamou they are short and ovoidal, as in Syrrhaptes. 



The caeca coli of the Tinamou are inferior to those of the Fowls, and relatively shorter than in the Rhea ; the 

 largest of the two is 3| inches long by J an inch in width at the widest part. These organs are not sacculated 

 as in the Rhea, and they have neither the delicate reticulated plicae of the Fowl nor the large longitudinal folds 

 of the Grouse and Sandgrouse ; in the Mooruk and the Emu they are short ; in the latter bird they are not an 

 inch in length six weeks after hatching. In this Tinamou the oesophagus is 7| inches in length; but the crop 

 projects from it 2 inches 8 lines, and is 1 inch 8 lines across. The proventriculus is 10 lines in length; the 

 gizzard If inch across, 1^ inch deep, and f of an inch thick. The duodenal fold is 3 inches long, and the in- 

 testine, from the gizzard to the caeca, 31 inches ; the colo-rectum is 5 inches long. The whole length of the 

 intestinal canal is 54 inches. The three slits in the soft palate (the two anterior being the median nares, and the 

 posterior slit receiving the Eustachian tubes) are in the Tinamou perfectly struthious. 



