406 CALIFORNIA ACADEMY OF SCIENCES. 34 
pital; near its middle it is connected with the posterior end 
ot the post-temporal, at which point it turns at a sharp 
angle and runs to the clavicle. The second bone is much 
larger, it is articulated to the basioccipital. Its posterior 
edge is nearly straight for its whole length, but its an- 
terior edge is produced and much swollen near its middle, 
and joins the post-temporal over the first bone, then runs 
to the upper end of the clavicle. 
The inner part of the clavicle and the coracoid are thin 
and pierced by many holes, so that the bone in places is 
little more than network. 
The hypercoracoid has a very large foramen; at its 
posterior edge is a projection which supports a thin bone, 
probably a dermal bone. 
The mesocoracoid is well developed. 
There are four actinosts; the first is long, but they 
rapidly decrease in size to the fourth, which is short and 
triangular. 
The first ray of the pectoral is large at the basal end, 
and hollowed out; it works directly on the hypercoracoid. 
d. Branchial Apparatus. 
The branchial apparatus is peculiar in the adult, in 
having gill-rakers somewhat resembling the filaments of 
a feather, on both sides of each arch and on the basi- 
branchial. They meet in a middle line between the arches 
and unite forming a continuous lattice-work screen, through 
which nothing but the very smallest bodies can pass. The 
pharyngeals have no teeth, but have gill-rakers similar to 
those on the arches; they are enclosed in sac-like pro- 
jections on each side. 
This description is taken from the skeleton of a large 
specimen 4 feet long. The gill-rakers are not united in 
young specimens. 
e. Other ‘Parts: 
