382 VERTEBRATE ANIMALS OF THE UNITED STATES 



Pustulate. Having minute pimple-like elevations. 



Pyloric caeca or appendages. Elongated, blind sacs opening into the intestine at the 

 point where it joins the stomach in fishes. 



Quadrate bone. The bone which joins the lower jaw, on each side, with the cranium, in 

 the lower vertebrates. 



Recurved. Curved upwards. 



Reticulate. Marked with a net-work of lines. 



Retractile. Capable of being drawn in. 



Rhombic. Diamond-shape. 



Rostral. Pertaining to the end of the snout. 



Rostral plate. A plate on the head of snakes and lizards at the tip of the snout. 



Rudimentary. Undeveloped. 



Rufous. Reddish; yellowish red. 



Rugose. Roughened or wrinkled. 



Ruminant. Chewing the cud. 



Russet. Reddish or yellowish brown. 



Sacral. Pertaining to the sacrum or the sacral region. 



Sacrum. The dorsal portion of the pelvis. 



Sanguivorous. Blood-sucking. 



Sauropsida. Reptilian-like vertebrates. 



Scalation. Pertaining to the scales. 



Scapula. The shoulder-blade. 



Segmental. Arranged in definite segments. 



Selachian fish. Sharks and skates. 



Sepia. Light brown. 



Septmn. A partition separating two spaces. 



Serrae. Notches; serrations. 



Serrate. Notched; jagged, like the teeth of a saw. 



Sessile. Attached by the base and not stalked. 



Setaceous. Bristly. 



Shoulder girdle. The bony girdle by which the skeleton of the fore legs is joined with the 

 trunk. 



Sinistral. Pertaining to or situated on or towards the left hand. 



Soft rays. Fin rays which are jointed and not stiff and sharp. 



Spatulate. Shaped like a spatula; more or less spoon or trowel-shaped. 



Sphenoid. One of the basal skull bones. 



Spine. A sharp projecting point. 



Spinous. Composed of spines. 



Spiracles. Openings of the head in certain fish and amphibians for the passage of respira- 

 tory water. 



Spiral valve. A spiral fold in the intestine of certain fish. 



Sternum. The breast-bone. 



Striate. Striped or streaked. 



Subcaudal plates. The ventral plates of a snake's tail; the urosteges. 



Subcorneal. Imperfectly conical. 



Subcylindrical. Imperfectly cylindrical. 



Subfusiform. Imperfectly fusiform. 



Subopercle. The membrane bone just beneath the opercle in fishes. 



Suborbital plate. The plate beneath the eye in snakes and lizards. 



Subrhombic. Imperfectly rhombic. 



Subspecies. A geographic race, which differs from the typical form of the species but 

 which cannot be completely separated from it. 



Sulcate. Grooved. 



