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Müller's descriptions; a nerve that is apparently the homologue of 

 the maxillaris trigemini of Amia, plus the motor nerve that innervates, 

 in that fish, the m. levator maxillae superioris. 



The second nerve of this group of nerves arises from the base 

 of the large anterior nerve as that nerve passes downward through 

 fenestra * It separates immediately into two parts, both of which run 

 downward and mesially along the lateral and ventral surfaces of the 

 velar muscles, and then directly to the dorsal and lateral surfaces of 

 the mouth cavity, where they are distributed, one running forward 

 and the other backward. They are thus palatine branches of the 

 trigeminal nerve and are the rami palatini of Müller's descriptions; 

 but Müller says that some of those nerves in B. heterotrema contain 

 motor fibres, which is certainly not true of the nerves in B. dombeyi. 

 v. Kupffer does not especially mention this palatine nerve, unless it 

 be the whole or a part of the nerve said by him to arise from his 

 third epibranchial ganglion. 



The third and most posterior of this group of nerves is the ramus 

 mandibularis. This nerve receives a large bundle of motor fibres from 

 the motor nerve of the complex, and then separates at once into two 

 parts, an anterior and a posterior one. The anterior nerve runs 

 almost directly downward along the external surface of the m. qua- 

 drato-palatinus, passes external to the m. hyo-copulo-glossus, and then 

 turns mesially and forward along the ventral surface of the mouth 

 cavity. It sometimes perforates the m. quadrato-palatinus near its 

 dorsal edge. It is the ramus hyoideo-dentalis n. trigemini of Müller's 

 descriptions. The posterior nerve runs downward and backward 

 immediately internal to the m. quadrato-palatinus and m. hyo-copulo- 

 glossus, and then backward in relation to the so-called tongue of the 

 fish. It is the ramus lingualis n. trigemini of Müller's descriptions. 

 The further course and distribution of these two nerves was not 

 traced. 



The motor trigeminal nerve, as it issues from its foramen through 

 the membranous cranial wall, lies ventral to the hind end of the maxillo- 

 mandibularis ganglion. It immediately turns downward and laterally 

 along the postero-lateral surface of the truncus maxillo-mandibularis, 

 passes through fenestra 1 , posterior to that truncus, and there im- 

 mediately sends a branch backward, ventral to what Ayers and Jack- 

 son call the superior process of the pterygo-quadrate cartilage. This 

 branch separates at once into two parts, one of which turns mesially 

 and the other laterally, beneath the cartilage. The two branches then 

 continue backward and go the one to the mesial one of the two parts 



