. Bulletin of the Museum of Comparative Zoology at Harvard College. Zoology; Zoology. EASTMAN: SHARKS TEETH AND CETACEAN BONES. 89 cochleae. We will now describe the different aspects of the subject selected for illustration, beginning with the external. External face (Fig. A). — The most obvious feature of the outer lip (1) of the bulla ossea relates to the presence of certain processes along the superior margin. There is one at either extremity, termed respec- tively the processus anterior (3) and proc. posterior (4), whose function is to unite the tympanic and petrous (2) bodies in the mann
. Bulletin of the Museum of Comparative Zoology at Harvard College. Zoology; Zoology. EASTMAN: SHARKS TEETH AND CETACEAN BONES. 89 cochleae. We will now describe the different aspects of the subject selected for illustration, beginning with the external. External face (Fig. A). — The most obvious feature of the outer lip (1) of the bulla ossea relates to the presence of certain processes along the superior margin. There is one at either extremity, termed respec- tively the processus anterior (3) and proc. posterior (4), whose function is to unite the tympanic and petrous (2) bodies in the manner already explained. These are the only points of contact where the two bodies are actually fused, and they are completely separated below by the. lb-- Fig. A. — Left tympano-periotic of the existing- Delphinaplerus leucas Pallas. External face, X J. The same numbers are used in Figs. A-F for the following parts: 1, Bulla tympanica (outer lip); 2, Petrosal; 3, Proc. ant. bullae; 4, Proc. post, bullae; 5, Proc. conicus bullae (= rudimentary inferior wall for external auditory meatus); 6, Proc. tubarius (= part of ante" rior process supporting so-called " accessory ossicle "); 7, Proc. sigmoideus (= rudimentary anterior wall of external auditory meatus); 8, Position of membrana tympani ; 9, pointed anterior extremity of petrous body; 10, Proc. ant. petrosi ; 11, Proc. post, (mastoideus) petrosi; 12, Hiatus epitympanicus; 13, Aptertura extern, aquaeductus vestibuli; 14, Aper- tura extern, aquaeductus cochleae; 15, Porus acusticus internus ; 16, bulla tympanica (inner lip); 17, Fissura tympano-periotica; 18, Orificium (Hiatus) tympanicum; 19, Aper- tura tympanica canalis Eustachii; 20, Groove for the nervus facialis ; 21, Fenestra cochleae. tympano-periotic fissure (IT). There are developed in the intermediate space between these processes two others, the more prominent of which is singularly formed, and receives the name of proc. sigmoideus (7). The smaller one
Size: 1610px × 1552px
Photo credit: © Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookauthorha, bookcentury1800, bookdecade1860, booksubjectzoology
