184 AX ATOMIC AL TECHNOLOGY. 



lacerated, or spheno-petrosal foramen. The opening" of this foramen on the ectal sur- 

 face of the skull is just within the mouth of the Eustachian canal. It perforates the lateral 

 edge of the cephalic projection of the bulla, and may be seen on most prepared skulls by 

 looking into the mouth of that canal. 



The existence of the Foramen lacerum medium in the cat is not mentioned by any of 

 the authorities, so far as we are aware ; but the foramen so named in this figure is between 

 the cephalic extremity of the pars petrosa and the alisphenoideum the position occupied 

 by the foramen lacerum medium in man, as stated by Quain, A, I, 62, and in the dog, as 

 stated by Flower, A, 101. This foramen in the cat also transmits an artery, which has 

 been called internal carotid in the table of foramina ( 562). It is so called since it anas- 

 tomoses with the cerebral vessels within the cranium, and arises from the carotid at th^ 

 proper place slightly centrad of the origin of the lingual. It passes along the carotid 

 canal and unites with a larger vessel extending along the mesal side of the bul!a. The 

 artery is imbedded in the wall of the Eustachian tubo in its passage along the Eustachian 

 canal to the foramen. 



Fm. ov., Foramen ovale. 



Fm. rt., Foramen rotundum. 



534 Fm. 1. a., Foramen lacerum anterius s. fissura sphenoidalis. Anterior 

 lacerated foramen or sphenoidal fissure. 



Fm. op., Foramen opticum, transmitting the Nervus opticus. 



535. Fm. pit. p., Foramen palatinum posterius Posterior palatine foramen. 

 There are usually two openings of the posterior palatine canal in the roof of the mouth as 

 shown in this figure. (See also Fig. 56.) 



Fm. pit. a., Foramen palatinum anterius s. Fm. incisore. Anterior palatine or 

 incisor foramen. 



536. Fs. tyh., Fossa thyrohyalis. This is the pit into which is inserted the 

 dorsal part of the Os hyoides ($ 224). 



537. Fs. (Fossa) mandibularis Mandibular or glenoid fossa. This receives the 

 mandibular condyle and articulates diarthrodially with it (Fig. 62). 



538. Ft. rt., Fenestra rotunda This opening connects the tympanum with the 

 scald tympani of the cochlea. In the living body it is covered with membrane. 



539. Ft. ov., Fenestra ovalis. This connects the tympanum with the vestibu/a, 

 In living bodies it is closed by the stapes and its connecting soft structures. 



540. M. a. e., Meatus auditorius externus External auditory meatus. This 

 extends from the side of the head to the ectal surface of the Membrana tympani. 



541. Margo alveolaris Alveolar margin or border of the jaw. In this border of 

 the jaw the teeth are implanted. 



O. supraoccipitale, az. Supraoccipital bone. 



O. exoc., Os exoccipitale. Exoccipital bone. 



O. basioccipitale, az. Basioccipital bone. 



O. basisphenoideum, az. Basisphenoid bone. 

 . O. alsph., Os alisphenoideum (Fig. 56). 



O. pt., Os pterygoideum. Pterygoid bone. 



O. praesph., Os praesphenoideum, az. 



O. orsph., Os orbito-sphenoideum (Fig. 56). 



O. frontis (Fig. 56). 



O. vm., Os vomeris. Vomer (Fig. 59). 



O. palatinum. Palate bone (Fig. 56). 



O. malare. Malar bone (Fig. 56). 



O. maxillare. Maxillary or upper jaw bone (Fig. 56). 



