GLOSSARY OF TECHNICAL WORDS AND TERMS 389 



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 bejng 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., 



Septimi. 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 res- 

 piratory 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. 



Subconical. 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. 



Subphylum. A main subdivision of a phylum. 



Subrhombic. Imperfectly rhombic. 

 Sulcate. Grooved. 



Superciliary plates. The plates just above the eye in certain snakes and lizards. 



Superior. In a higher or more elevated position. 



Supplementary maxillary bone. A small bone just above the ma.xillary in certain fish. 



