344 REPTIL1A. 



The external ear is a flap, like the upper eyelid, covering the rnem- 

 brana tympani ; which is bony at the upper part, like the orbit of the 

 eye. The membrane is very superficial, being immediately under this 

 flap, looking upwards and a very little downwards, and is rather convex 

 externally, especially in the middle. The Eustachian tube opens behind 

 the posterior nares, by one common orifice, to both of which there is a 

 doubling of the membrane of the fauces like a clitoris within the 

 prepuce. The Eustachian tube soon divides into two ; at this division 

 a cavity soon runs forwards a little way, and terminates in a csecum ; 

 each Eustachian tube passes outwards in a bony canal all the way to 

 the tympanum, becoming smaller as it passes in : thence it passes back- 

 wards, diverging. There is an irregular fasciculated surface, I suppose 

 the tonsils, or a glandular substance 1 . 



The thyroid cartilage is broad and flat, a good deal the shape of the 

 mouth of a shovel ; it stands prominent in the mouth at the root of the 

 tongue, where it appears as the epiglottis 2 . There are two glandular 

 bodies on the neck, close to the upper part of the thorax on each side 

 of the trachea, a good deal like the thymus and some small ones scat- 

 tered near them, having lymphatics passing into them. 



There are pretty broad cartilages fixed to the lower edge of most of 

 the true ribs, like the bony processes in birds ; their lower edges over- 

 lap the ribs below. They have two false ribs on each side at the upper 

 part of the thorax. 



The lungs are two lobes, one on each side ; they lie pretty far back, 

 and do not come forwards as in the human : they are, therefore, oblong ; 

 they are loose, except at the lower end, where they come in contact with 

 the river, to which they adhere all round that surface of contact, which 

 forms a capsule between them and the liver ; the left lobe adheres by a 

 broader surface ; it also adheres to the anterior part of the stomach on 

 the left of the oesophagus 3 . 



The apex of the heart 4 adheres to the pericardium, in which adhesion 

 passes a vein from the heart to the liver; this is one of the coronary 

 veins. Besides the two carotids, as in the more perfect animals, they 

 have two running up the fore-part of the neck covered by the muscles, 

 as in birds. 



The fat is not oily, nor solid like that of an ox, nor is it quite so soft 

 as the human : it is of a brownish ash-colour, and has very much the 

 appearance of being glandular, being similar to some conglomerated 

 glands, such as the pancreas. 



1 [Hunt. Prep. Phys. Series, No. 1577.] 



2 [The above description applies to the basihyal cartilage. See Note 3, p. 342.] 

 s [Hunt. Preps. Phys. Series, Nos. 1118—1123.] * [lb. Nos. 921, 922.] 



