_a._ =N. frontalis.=--The frontal nerve passes along the lateral border of the superior oblique muscle and then laterad of the pulley to near the middle of the supraorbital crest of the frontal bone. Here it passes out of the orbit and is distributed to the integument of the upper eyelid and the adjacent region at the side of the nose. _b._ =N. infratrochlearis.=--The infratrochlear nerve passes between the superior rectus and the superior oblique in the first part of its course. It then passes ventrad of the superior oblique and ventrad of the pulley to be distributed to the integument of the upper eyelid near the inner angle. _c._ =N. ethmoidalis.=--The ethmoidal nerve passes along with the ethmoidal artery through the ethmoidal foramen (or foramina) in the orbital plate of the frontal bone. It is finally distributed to the mucosa of the nose and to the cartilage and integument of the snout. _d._ =N. ciliaris longus.=--The long ciliary nerve arises from the ophthalmic and passes along the optic nerve to be distributed to the eyeball. It divides into several branches before penetrating the sclerotic. One or two small communicating branches to the =ciliary ganglion= are given off at about the same point as the long ciliary nerve. (For a description of this ganglion see the account of the oculomotor nerve, page 369.) 2. =N. maxillaris.=--The maxillary nerve, the second division of N. trigeminus, rises from the semilunar (Gasserian) ganglion and leaves the skull by the foramen rotundum. It is the sensory nerve of the palate, upper teeth and upper lip, and of part of the forehead and cheek. On leaving the foramen the maxillary nerve divides into three branches, the two =infraorbital= nerves (Fig. 154, _f_) and the =sphenopalatine= (Fig. 154, _g_). Two smaller branches are likewise given off either within or just outside of the foramen, the =lachrymal= nerve (Fig. 154, _j_) and the =zygomatic= (subcutaneus malæ) (Fig. 154, _i_). _a._ =N. lachrymalis= (Fig. 154, _j_; Fig. 155, _m_).--The lachrymal nerve passes along the periorbita to the lachrymal gland (Fig. 154, 11), to which it gives branches. It then continues caudad of the zygomatic process of the temporal to the integument; here it turns caudad and is distributed to the integument in the region between the eye and the external ear (Fig. 155, _m_). It anastomoses with the zygomatic branch of the seventh nerve (Fig. 155, _h_). _b._ =N. zygomaticus= (subcutaneus malæ) (Fig. 154, _i_).--This arises with the preceding and follows it for some distance. It passes through a foramen in the frontal process of the malar bone and is distributed to the lower eyelid and adjacent integument.