GLOSSARY. Tit 
name applied to the anterior basal fin 
cartilages in the Elasmobranchii. 
Pterotic (Gr. pteron, a wing ; ous, ofos, the ear).—An 
ossification between the pro-otic and epi-otic 
bones in some Vertebrata. The name is 
given by some human anatomists to one of 
the osseous deposits in the embryonic petro- 
mastoid. 
Pterygoid (Gr. pteron, a wing ; ezdos, shape).—A pair 
of bones behind or lying partly on the 
palatines of some Vertebrata ; in human 
anatomy they are termed the internal ptery- 
goid plates of the sphenoid bone. 
Pubis (L. pubes, the region of the groin)—A_ bone of 
the pelvis; in human anatomy the anterior 
portion of the os zznominatum. 
Pygostyle (Gr. puge, the rump ; szz/os, a style, pen).— 
A bone in most birds supporting the tail 
feathers ; the ploughshare bone. 
Quadrate (L. guadratus, square).—A bone of the skull 
articulating with the lower jaw in all Verte- 
brata below the Mammalia. 
Quadrato-jugal (L. guadratus, square ; jugum, a 
yoke)—A bone formed by the union of the 
quadrate and jugal in some Vertebrata, in 
others a bone situated behind the jugal and 
maxillary bones. 
Quadrato-palatine (L. guadratus, square ; palatus, 
the pallet)—A bone formed by the union of 
the quadrate and palatine in some Verte- 
brata. 
