GREAT BLUE HERON. 599 



turn is 5 twelfths, and it terminates in a globular cloaca, j k, 1 inch 10 

 twelfths in diameter. 



Trachea 22 inches long, considerably flattened, 5 twelfths in breadth 

 at the upper part, 4| twelfths at the middle, and lastly contracting to 

 3|^ twelfths. The rings cartilaginous, 270, the last 4 dimidiate. The 

 right bronchus has 25 rings, the left 28 ; they are wide and compressed. 

 There is a pair of cleido-tracheal muscles, passing from the thyroid 

 bone to near the middle of the furcula. The lateral muscles are thin 

 and slender at the upper part, at the lower part thicker and expanded 

 over the whole sm-face before and behind ; the anterior part gives off 

 the sterno-tracheal, at the distance of 9 twelfths from the last ring, and 

 the posterior part passes in the form of a compact slip, to the last half 

 ring. 



GREAT BLUE HERON. 



Arvea herodias, Linn. 

 PLATE CCXI. Vol,. III. p. 87. 



Adult Male. The interior of the mouth is similar to that of the 

 last species, there being three longitudinal ridges on the upper man- 

 dible ; its width is 1^ inch, but the lower mandible can be dilated to 

 2^ inches. The tongue is 3| inches long, trigonal, and in all respects 

 similar to that of Ardea occid&ntalis. The oesophagus is 24 inches in 

 length, opposite the larynx its width is 2| inches, it then gradually con- 

 tracts to the distance of 7 inches, becomes 1 inch 10 twelfths in width, 

 and so continues until it enters the thorax, when it enlarges to 2 inches 

 and so continues, but at the proventriculus is 2g inches in breadth. 

 The stomach is roundish, a little compressed, 2^ inches in diameter ; 

 its muscular coat thin, and composed of a single series of fasciculi, its 

 inner coat soft and smooth, but with numerous irregular ridges. There 

 is a roundish pyloric lobe, 9 twelfths in diameter. The proventricular 

 glands form a belt 1 inch 4 twelfths in width ; at its upper part are 

 10 longitudinal irregular series of very large mucous crypts, the right 

 lobe of the liver is 3 inches in length, the left 2 inches ; there is a gall- 



