22 THE VOYAGE OF H.M.S. CHALLENGER. 
glacialis is represented!). In the Oceanitidze and Diomedeinz this epithelium is softer ; 
its character in other Petrels is but an exaggeration or reproduction of that existing in 
some other birds, particularly that occurring in such storks as Xenorhynchus. 
The displacement of the pyloric orifice of the gizzard to the left necessitates a corre- 
sponding change in the commencing duodenum, so that this at first ascends in an upward 
curve towards the right before it returns to form the backwardly-directed loop, character- 
istic of Aves and Mammalia, round the pancreas (PI. II. fig. 1, p.). 
This peculiar upward curve of the commencing duodenum, the singularly small inverted 
stomach, and enormously deep proventriculus are all peculiar, so far as I am aware, to the 
group of Tubinares, though universal amongst them, and no other bird yet examined 
has, so far as I know, a similar disposition of these viscera.” 
The intestinal cxeca are entirely absent in all the Oceanitide, but are, with one 
exception, present, though of small size, in the Procellariide. They are always short 
and globular, and closely connected to the intestine, so as to appear as mere nipple- 
like projections from it. Plate II. fig. 3 represents those of Majaqueus slightly en- 
larged. They are usually situated quite close to the cloaca, the large intestine in nearly 
all the Tubinares being quite short; the length of the ceca themselves rarely 
exceeds ‘25 inch, except in the very largest species (vide table, p. 23). In five speci- 
mens (one a nestling) of Cymochorea leucorrhoa that I have examined, I find only 
a solitary caecum, lateral in position, developed, owimg apparently to the abortion of 
its fellow. As Mr. Swinhoe in his description of Cymochorea monorhis® also records 
the cecum as single, it is probable that the existence of such a single caecum is 
a character of the genus Cymochorea. It is not unusual, I may observe, in a group 
of birds in which the czeca are of small size, and probably of no physiological im- 
portance, to find specimens or species with the normal number of caeca reduced by 
one. I may give as instances Mergus albellus (cf: Hunter, Observ., vol. ii. p. 325; and 
Garrod, Coll. Papers, p. 220) amongst the Anseres, and Plotus anhinga (Garrod, l.c., 
p- 345) amongst the Steganopodes, not to mention all the Ardeidz amongst the 
Herodiones. In Halocyptena, in the only specimen yet examined, I could find no trace 
of any ceeca at all, so that the tendency to their disappearance already observable in 
1 The figure of Carus and Otto (Tabule Anat. Comp. Illustr., part 4, t. vi. figs. 15, 16) of the epithelium of the gizzard 
of Fulmarus glacialis does not at all faithfully represent what I have seen in two (quite fresh) specimens of that bird, 
nor have I ever in other Petrels seen epithelium of such a corneous and pavement-like nature as that figured by them. 
I have, therefore, had one of my specimens carefully drawn of the natural size. In this place it will be well to recall 
the still more highly developed gastric epithelium of some of the Fruit-pigeons (Phenorhina goliath and Carpophaga 
latrans) described by Verreaux and Des Murs, Viallanes and Garrod (vide antea, Report on the Birds, pp. 152-154). 
2 The description of these parts in the Little Auk (Alca alle) given by Professor Owen (Anat. Vert., vol. ii. p. 163), 
and originally due to Home (Lect. Comp. Anatomy, i. pp. 283, 284, 1814) does not all apply to that bird (cf. the figure 
and description given by Macgillivray in Audubon’s Ornithogical Biography, iv. pp. 306-809), and probably refers to 
some member of the Tubinares. 
3 Tbis, 1867, p. 387. I have examined the type of this species, which is now in Mr. Seebohm’s collection, and find 
it to be a true Cymochorea. 
