COMMON AMERICAN GULL. 639 



to a narrow emarginate point, and trigonal. (Esophagus 7 inches 

 long, extremely wide, its breadth being IJ inch; that of the proven- 

 triculus 1 inch 9 twelfths. The stomach is rather small, elliptical, 

 1 inch 5 twelfths long, 1 inch 2 twelfths broad ; its lateral muscles dis- 

 tinct and of moderate size, the lower prominent, the tendons large, the 

 epithelium dense, with very prominent large rugae ; the inner coat of the 

 oesophagus is longitudinally plicate ; the proventricular belt 1 inch in 

 breadth, with six broad plates. Intestine 30 inches long, its width at 

 the upper part 5 twelfths, diminishing to 2§ twelfths, cceca 3 twelfths 

 long, 1 twelfth broad, 3 inches distant from the extremity, rectum 

 5 twelfths broad, with a globular cloaca 9 twelfths in diameter. The 

 duodenum curves at the distance of 2^ inches, advances toward the liver 

 in the usual manner, and is afterwards very regularly coiled in an el- 

 liptical form, with 10 bends. Trachea 5 inches long, from 3 twelfths 

 to 2^ twelfths in breadth, not flattened, its rings slightly osseous, 130. 

 Bronchi wide, of 20 half rings. The lateral and sterno-tracheal mus- 

 cles are slender, and a sUp on each side extends to the last half ring of 

 the trachea^ 



CAYENNE TERN. 

 Sterna cay an a. Lath. 



PLATE CCLXXIII. Vol. III. p. 505. 



The width of the mouth is 1^ inch ; the palate flat, with 2 promi- 

 nent papillate ridges, the anterior part with five faint elevated lines ; 

 the posterior aperture of the nares linear, 1\ inch long, margined with 

 papillae. Tongue 1 inch 11 twelfths long, narrow, fleshy above, horny 

 beneath, channelled, and tapermg to a slit horny point. CEsophagus 

 9 inches long, at its commencement 1 inch 9 twelfths wide, presently 

 after 1| inch, then contracting to 11 inch, and within the thorax en- 

 larging to 1| inch. In its form and structure it is exactly similar to 

 that of the Gulls. The stomach is of moderate size, 2 inches long, 

 1 inch 9 twelfths broad ; its lateral muscles rather thin ; the epithelium 



