SKULE 879 
The PreryGorps are rod-shaped bones articulating in front 
with the posterior end?! of the Palatines, or also with the adjoining 
part of the sphenoidal rostrum, and behind with a process of the 
Quadrates. In many birds an additional articulation exists between 
the Pterygoids and the Basisphenoid by means of the BASIPTERY- 
GOID PROCESSES (p. 28). 
The QUADRATES connect the lower jaw with the cranium, beside 
serving for the posterior end of the Pterygoids, and lastly are con- 
nected with the Maxilla and Premaxilla by two thin rod-shaped 
bones—the Quadrato-jugal and the Jugal. 
The Mandibula forming the lower jaw is composed of a con- 
siderable number of bones, most of which developing from membrane 
invest the primitive cartilaginous portion, known as Meckel’s Car- 
tilage, and soon fuse with each other. The os articulare forms the 
articulation with the Quadrate, and bears on its inner side the 
processus mandibularis internus, which serves for the insertion of 
part of the digastric muscle, or that which opens the mouth. The 
os angulare forms the posterior end of the mandible, and is frequently 
produced into a processus mandibularis posterior, likewise serving for 
the insertion of the digastric muscle. Its shape and size are of 
taxonomic value. The greater part of the Mandible is formed by 
the Dentary, so called because in it the teeth when present are 
lodged. In Hesperornis, Ichthyornis and apparently Gastornis the 
two halves of the Mandible were movably connected at the distal 
end: in recent birds they are fused together and ossify from the 
point of meeting. The Supra-angular or Coronoid element fills the 
space between the Articular and Dentary on the upper or anterior 
side, and serves for the insertion of part of the temporal or masseter 
clidz, Columbe, Turnix, Ralli, Grues (excl. Cariama and Rhinochetus, which 
are incompletely Desmognathous), Gallinew, Opisthocomus, Trogonide, many 
Striges, Trochili, Caprimulgus, Nyctibius, Pici, Megalema and, as first men- 
tioned, Purnariing. 
Parker drew attention to the existence of three kinds of Desmognathism :— 
(1) Direct —where the maxillo-palatine processes fuse directly with each 
other, either incompletely as in Cariama, or completely as in most Accipitres 
and Anseres, with or without additional help from the internasal septum, 
(2) Indirect—where the fusion of these processes is effected solely by that 
septum, either incompletely as in Megalema, or completely as in Aquila, 
Vultur, several Striges and Alcedinidx. 
(8) Double—where those processes and the palatines meet in the middle line 
and form a broad solid roof, as in Podargus and Buceros. 
The following are Desmognathous :—Dromezus, Anseres, Steganopodes, Herodit, 
Pelargi, Accipitres, Psittaci, Coccyges, Alcedinidx, Meropide, Todide, Upupide, 
Bucerotide, Coliidex, Bucconidz, Galbulidw, Steatornis, Chordiles, Podargus 
and Rhamphastidz ; lastly, the incompletely Desmognathous Cracidz, Cariama, 
Rhinochetus and various Striges. 
1 At page 744 the ‘‘anterior end” was inadvertently stated, 
