( 645 



WILSON'S PETREL. 



ThALASSIDROMA WlLSONII, BONAP. 

 PLATE CCLXX. Vol. Ill, p. 486. 



The palate is marked behind with four longitudinal ridges, which 

 are papillate, and before with three ridges ; the mouth 4^ twelfths in 

 width, but capable of being dilated 

 to 9 twelfths ; the tongue \ inch 

 long, triangular and acuminate, at 

 the base concave and emarginate, 

 flat above, with a sUght median 

 groove. The lobes of the liver are 

 equal, their length 7^ twelfths. The 

 oesophagus, « ft, has a uniform width 

 of 3 twelfths until it enters the tho- 

 rax, when it at once expands into an 

 immense ovate sac, hcde, 1 inch 11 

 twelfths long, viewed anteriorly 1 

 inch 1 twelfth in breadth, laterally 

 1 inch 2 twelfths. This sac is 

 formed, properly speaking, of the 

 proventriculus ; its walls are ex- 

 tremely thin and transparent, and 

 it is studded all over with roundish 

 glandides placed at a considerable 

 distance from each other. It cm'ves 

 upwards in front, and becomes narrowed to 2 twelfths, ending in the 

 stomach, which is an extremely diminutive gizzard, of an oval form, 

 only 3| twelfths long, and 3 twelfths in breadth. The stomach is thus 

 reversed in position, its fundus being anterior ; and accordingly the in- 

 testine, fg h i, comes off from its left instead of its right side, forms a 

 semicircular sweep round the fundus, then passes backward for 1 inch, 

 to/, bends forward to the liver, at g, and forms a number of loops, ghi, 

 making in all 9 turns. The duodenum is 1 inch | twelfth wide, and 

 the intestine continues so for half its length, when it gradually contracts 



