56 Journal of Entomology and Zoology 
side of the anterior portion of the skull. Each is so placed that one 
half of its surface articulates with the dorsal surface of the skull, 
while the other half forms a portion of the side of the skull. 
Through the center of the ectethnoid there is a dividing ridge which 
separates its dorsal surface from its lateral surface. The dorsal 
surface articulates anteriorally with the maxillary and the nasal, 
and posteriorally with the frontal. The lateral surface articulates 
anteriorally with the maxillary and posteriorally with the frontal; 
a small portion remains between these two articulations and this 
portion bounds part of the opening into the olfactory fossa. 
The maxillaries (4) are long slender bones, which, together 
with the premaxillaries bear the teeth of the upper jaw. The 
maxillary articulates only anteriorally and diverges posteriorally to 
form a long rather slender process extending about one-half the 
length of the skull. Before the maxillary articulates with the main 
body of the skull it diverges on the inner side into two portions; 
the upper portion articulates with the dorsal bones of the skull, 
while the lower portion articulates with the ventral bones. The 
hollow depression resulting from these two divergences forms the 
opening into the olfactory fossa. Dorsally the maxillary articu- 
lates with the nasal and the ectethnoid; and ventrally with the pre- 
maxillary and the squamo-palatine. 
The frontals (5) form a little less than one-half of the dorsal 
surface of the skull. They lie in contact with one another for about 
two-thirds of their length, diverging anteriorally to form a pair of 
short premaxillary processes, and diverging posteriorally to form 
two processes,—a blunt rather broad parietal process and a long 
slender process which articulates with the squamosa! bone. On the 
ventral surface of each frontal is an out curving ridge which serves 
for the attachment with the sphenethnoid. 
