URINATKICES. 
199 
eyes rather small ; aperture of ear very small. Tongue 
slender, pointed; oesophagus wide, with moderately thick 
walls ; proventriculus large ; stomach rather large, round- 
ish, with the muscular coat rather thick, the tendons 
roundish, the epithelium thickish and rugous ; intestine 
long and rather wide, with moderate coeca ; the rectum 
with a very large globular dilatation. Legs generally 
very short, and placed very far behind, so as to cause a 
nearly erect attitude ; tibia bare for a very short space ; 
tarsus short, extremely compressed ; toes four, all much 
compressed, and scutellate ; the anterior long, and web- 
ed ; claws small, and blunt. Plumage close, short, blend- 
ed on the head and neck, firm and compact above. 
Wings narrow, pointed ; tail extremely short. 
The Urinatrices are essentially piscivorous, although 
several species feed also on insects, reptiles, Crustacea, 
and other small aquatic animals, and some on mollusca. 
They nestle on the ground or on rocks, but sometimes 
deposit their eggs on the bare surface, or in holes, with- 
out any nest. The young remain in the place where 
they have been hatched for some time. Their flesh is 
dark-coloured, disagreeably-flavoured, and unfit for food. 
The males are larger than the females. All the spe- 
cies are in some degree migratory. They fly with a 
rapid, direct motion, scarcely ever walk, stand in an in- 
clined, nearly erect posture, swim and dive with the 
greatest address, using their wings as well as feet for 
propelling themselves under water. The number of 
species that occur in Britain is only fourteen ; but of se- 
veral of them the individuals are extremely numerous* 
