150 EDWARD PHELPS ALLFS, JUN. 



and transmits the nnited stems of the hyoideo-mandibularis 

 facialis, maxillo-mandibularis trigemini, and buccalis facialis. 

 In one of my embryos, dissected by Mr. Nomura, a fourth 

 trigemino-facial foramen was found. It lay slightly in front 

 of the ophthalmicus superficialis foramen, was small, and 

 transmitted a small bundle of fibres which immediately joined 

 the ramus ophthalmicus superficialis. The relative size of 

 the two foramina by which the ophthalmicus superficialis thus 

 issued from the skull in this specimen would lead one to suppose 

 that the smaller foramen transmitted the general cutaneous 

 component of the nerve, the larger one transmitting the united 

 lobus trigemini and tuberculum acusticum components. 



Ramus Ophthalmicus Superficialis. 



The ramus ophthalmicus superficialis, after it issues from 

 its foramen, immediately becomes ganglionic, as already stated, 

 and is a broad, flattened nerve, which lies against and runs 

 forward along the side wall of the skull, immediately ventral 

 to the projecting and overhanging roof of the orbit. The 

 nerve is here formed of two perfectly distinct parts — a large 

 ganglionated dorsal portion, and a small non-ganglionated 

 ventral one. The dorsal portion contains the fibres destined 

 to supply the sensory organs of the lateral canals and those 

 of the ampullae, and may be referred to as the special sensory 

 portion. The ventral portion contains the general sensory 

 fibres of the nerve. 



The descriptions of this nerve and of the others that follow 

 are based entirely on the conditions found in the 12"2 cm. 

 embryo examined by sections, and hence do not agree exactly 

 with the figures. 



Immediately outside its foramen the ophthalmicus super- 

 ficialis gives off two branches, one arising from the dorsal, 

 ganglionic portion of the nerve, and the other from its ventral, 

 non-ganglionated portion, this latter branch running upward, 

 as a flat nerve, alo-ng the mesial surface of the special sensory 

 portion of the nerve. Dorsal to the main nerve the two 

 branches anastomose to a greater or less extent, and together 



