No. 3.] MUSCLES AND NERVES IN AMIA CALVA. 501 
times through the cartilage immediately in front of the alisphe- 
noid, and sometimes through the anterior edge of that bone 
(acufr, Figs. 9-11, Pl. XXI). In embryos the vein ov! could be 
traced inside the sclerotic outward and forward toward the optic 
lens, accompanied by the ciliares longi. After it has joined the 
orbital vein, the latter enters the upper, lateral chamber of the 
eye-muscle canal through the large orbital opening of that canal, 
lying external to the profundus ganglion and dorsal to the ciliares 
longi. 
The second and larger of the two optic veins, ov, issued, in 
the large specimen used for illustration, by two main openings 
and other smaller ones through a porous portion of the sclerotic 
lying immediately below and lateral to the optic perforation. It 
arises from the choroid gland and other structures in the interior 
of the eye, one branch being traced through the pigment layer 
of the retina to its inner surface. Having issued from the eye- 
ball it runs inward and backward immediately below the opticus, 
and enters the orbital opening of the eye-muscle canal, passing 
above and in front of the inferior branch of the oculomotorius, 
between the rectus superior and the rectus inferior, and above 
the efferent pseudobranchial artery. Its further course was not 
traced in the adult. In 40 mm.and 50 mm. specimens it sepa- 
rates near the origins of the internal and inferior recti into two 
parts, one of which continues backward below the rectus exter- 
nus while the other turns upward in front of that muscle and 
joins or is joined by the orbital vein. The united veins then 
run backward, at first below the trigemino-facial ganglion, then 
internal to it, and finally above it, the larger portion of the vein 
passing through the ganglion. It then issues through the facial 
foramen and joins the jugular vein. The other portion or branch 
of the vein ov, the portion continuing backward below the rectus 
externus, reaches the external surface of the lining membrane 
of the eye-muscle canal and continues inward and backward 
along that membrane to the hind end of the hypophysis, where 
it turns inward behind that organ, between it and the saccus 
vasculosus, and joins the corresponding vein of the opposite side 
of the head. That part of the vein that lies in the orbit is 
unquestionably the structure considered by Sagemehl (No. 104, 
