GREAT NORTHERN DIVER. 
177 
layer composed of transverse * or circular fibres, the internal of equally 
distinct longitudinal fibres, which are not straight, but irregularly undulated. 
The inner, or mucous coat, when contracted, falls into longitudinal plaits. 
The proventriculus is 2f inches long, the glandules large, roundish, simple, 
and disposed in a continuous belt. Over this part, the transverse muscular 
fibres are remarkably developed. The right lobe of the liver is 5 t inches 
long, the left lobe 5^. The heart is very large, of a broadly conical form, 8 
inches long,.2| inches in breadth. The stomach is three inches long, 24 in 
breadth of an elliptical form, a little compressed ; its lateral muscles 9 lines 
in thickness, and composed of strong large fasciculi ; the tendons 1 J inches in 
diameter ; the cuticular lining thick, its upper and lower parts marked with 
strong longitudinal ridges having numerous transverse fissures ; the grinding 
surfaces irregularly wrinkled, with a deep fissure down the middle of each. 
The pylorus is 8 lines in diameter when distended, and is destitute of valve, 
but has a strong prominent rim. In the stomach were remains of fishes, and 
some pebbles, chiefly quartz, the largest 4 lines long. The intestine 
measures 6 feet 6 inches in length, and varies in diameter from 8 to 6 lines. 
The rectum is 3£ inches long, the cloaca extremely large, forming a cavity 
about 3 inches in diameter. The coeca are 1| inches long, cylindrical, 
rounded at the extremity ; one of them 7 lines, the other 9 lines, in diameter. 
The trachea, when moderately extended, measures 134 inches in length, 
inconsiderably depressed, its transverse diameter at the upper part 9£ lines, 
at the lower 64 lines ; the rings cartilaginous, of moderate breadth, uniform, 
with a contraction in the middle before and behind, their number 134, the 
four lowest united. The bronchi are composed of about 20 narrow cai’- 
'tilaginous half rings. The contractor muscles are very broad, but thin, their 
fibres irregularly disposed in front ; they become thicker and narrower 
toward the lower part, and are continued beyond the sterno-tracheal muscles, 
which come off from the 20th ring from the inferior larynx, to the mem- 
brane between the last tracheal and first bronchial ring. 
Vol. VIII.— 23 
