ESPECIALLY MYCTOPHOIDS 15 
spo 
inf.s.c 
pa 
o.inf.s.c 
pto 
Op.s.c 
st 
f.d.pt 
epo st.s.c 
Fic. 5. Ichthyotringa delicata (Hay). Neurocranium in dorsal view. The anterior end 
of the snout is absent and the broken line on the right side of the figure indicates the 
course of the sensory canals. From B.M.N.H. P.48831. 
orbital sensory canal passed forwards within the pterotic to enter the sphenotic. 
After contacting the supraorbital sensory canal in the frontal the infraorbital canal 
passed through the sphenotic laterally and down into the last infraorbital bone. 
The sphenotic projects laterally from the frontal. The greatest width of the neuro- 
cranial roof is between these extremities of the sphenotic extensions. The sphenotic 
also inclines ventrally. Dorso-laterally the upper surface of the sphenotic is ex- 
cavated for the reception of the last infraorbital bone. 
The pterotic forms the postero-lateral edge of the skull-roof and extends consider- 
ably on to the roof. Antero-medially the pterotic is covered by the backward exten- 
sion of the frontal, but postero-medially it overlaps the lateral edge of the parietal 
forming the roof of the post-temporal fossa. The pterotic contacts the sphenotic 
anteriorly and the epiotic posteriorly, the supratemporal lying dorsal to the junction 
with the epiotic. The dorsal surface of the pterotic is smooth but dorso-laterally 
several elongated pores open into the tube which housed the otic branch of the infra- 
orbital sensory canal. The most posterior pore is the largest and received the sensory 
