308 SPECIAL ANATOMY. 



Arising above the Optic Nerve. 



c. Supraorbitalis, arises where the ophthalmic artery crosses the optic 

 nerve, passes between the roof of the orbita and m. levatorpalpebr. sup., passes 

 through foram. supraorbital., upwards, and divides into an external and in- 

 ternal branch, ascending upon the frontal bone, for corrugat. orbicular, and 

 frontalis and skin of the forehead. 



d. Ciliares (for. choroidea, corp. ciliare and iris). 



1. Posticce s. breves, arise, often from a superior and inferior common trunk, 

 pass along the optic nerve in a tortuous manner, surrounding it in clusters, 

 perforate the sclerotica with it, and spread out in the choroidea and proc. 

 ciliares, with ten to twenty branches. 



2. Medics s. longa, an external and an internal ; they perforate the sclero- 

 tica rather farther from N. opticus, pass between sclerotica^ and choroidea 

 as far as lig. ciliare, where they divide, unite to form circulus iridis major, 

 out of which also the circulus iridis minor arises. 



3. AnticcB (six to twelve branches of the Artt. musculares, or lacrymalis 

 and supra-orbitalis), give some branches to the fascia, perforate the scle- 

 rotica not far from the cornea, and open into the circulus iridis major. 

 Their number is indefinite. 



e. Rami musculares, a superior smaller (sometimes wanting), supplies mm. 

 levatorpalpebr., reclus and obliquus superior; an inferior passes between n. 

 opticus, and m. rectus inferior supplies this, and rect. externus and obliq. infe- 

 rior ; gives offciliar. anticce. 



Arising on the inner side of the Optic Nerve. 



f. Ethmoidales, a posterior and an anterior (larger), pass under m. obliq., 

 through the foram. ethmoidalia out of the orbit into the cranial cavity, divide 

 (each) upon the superior surface of the cribriform plate into two branches for 

 the dura mater and nasal cavities. The anterior gives ; 



1. Meningea antica, for thefalx cerebri, along the coronal suture. 



2. Nasalis anterior, passes through an anterior foramen to the anterior part 

 of the labyrinth and the septum and anastomoses with branches of the 

 Spheno-palatina. 



g. Palpebrales s. targets, arise close before the trochlea. The inferior passes 

 behind lig. palpebr. intern, downwards and outwards, and passes close to the 

 free border of the lid, between the cartilage and muscle of the inferior eyelid 

 as far as the outer angle, forming an arch (arcus tarsus infer.} and anastomos- 

 ing with the lacrymalis and infraorbitalis , where a branch for the mucous 

 membrane of the nasal canal then passes off. The artery of the superior eye- 

 lid descends to the superior lacrymal punctum, then passes outwards, like 

 the inferior (arcus tarseus superior}, and anastomoses with the lacrymal, fron- 

 talis, temporal, superfic. 



h. Nasalis (s. dorsalis nasi), terminal branch of ophthalmica, on the internal 

 superior angle of the orbita, passes out of these over lig. palpebr. intern into 

 the face, and divides after it has once given off: 



