230 ALUS. [Vol. XVIII. 



ulare, from the corresponding surface of the dorsal two thirds of 

 the procoracoid, from the adjoining surface of the clavicle, and 

 from the dorsal half or two thirds of the mesial surface of the 

 membrane that fills the fenestra between the clavicle and pro- 

 coracoid. Its fibers run upward and backward, and, becoming 

 tendinous, are inserted on the proximal ends of all of the dermal 

 rays excepting sometimes certain of the ventral ones. 



The nervus pterygialis enters the muscles of the fin at the 

 ventral edge of the superficial adductor muscle. There it turns 

 upward between the superficial adductor and the ventral one of 

 the two deeper muscles, until it reaches the dorsal edge of the 

 latter muscle, where it turns outward, that is laterally, between 

 the two deeper muscles, and enters its foramen in the scapulare. 

 There it turns downward between the superficial and deeper lateral 

 muscles, as already stated. Branches are given by it to each of 

 the three mesial muscles as well as to the lateral ones. 



Neurology. 

 I . Brain. 



To show the apparent origins of the several nerves, and the re- 

 lations of their roots to the different parts of the brain, a super- 

 ficial examination of the latter structure was necessary, and two 

 views of it are given. It presents the usual teleostean form 

 and characteristics, and varied greatly in the form and relative 

 proportions of its different parts in diflferent specimens; but 

 whether this was due to actual variations in the structure, or to 

 the efifect of reagents, was not investigated. 



The optic lobes are large, having in this a direct relation to the 

 largely developed eyes. They project laterally considerably be- 

 yond the other parts of the brain, and overhang and lie directly 

 upon the roots of the third, fourth, fifth and seventh nerves. 

 They also overhang the anterior parts of the membranous ear, 

 the anterior semicircular canal, on each side, being pushed later- 

 ally and backward into a strongly inclined position. The anterior 

 part of this semicircular canal, on each side, lies against and is 

 slightly embedded in, the lateral surface of the optic lobe, that 

 surface of the lobe being presented laterally, ventrally, and 



