MUSCLES OF THE HEAD. 221 



7. Great Supermaxillo-nasalis. (Fig. 110 3 19.) 



Synonyms. The pyramidalis-nasi of Bourgelat. The caninus of Man. ( Dilatator naris 

 lateralis Percivall.) 



Situation Direction Form Structure. This muscle, situated on the 

 side of the face, between thb two branches of the supernaso-labialis, in an 

 almost vertical direction, is of a triangular form, and slightly tendinous at its 

 summit. 



Attachments. It has its origin, by the aponeurotic fibres of its summit, 

 from the external face of the superrnaxillary bone, below its ridge. It 

 terminates, by its base, on the skin covering the external wing of the nostril, 

 its most posterior fibres being confounded with those of the orbicularis of 

 the lips. 



Relations. Outwardly, with the skin and the inferior branch of the 

 supernaso-labialis ; inwardly, with the anterior branch of that muscle, and 

 with vessels and nerves. 



Actions. It dilates the external orifice of the nasal cavity, by pulling 

 outwards the external wing of the nostril. 



8. Small Supermaxillo-nasalis. (Fig. 110, 25.) 



Synonyms. The nasalis brevis, and portion of the subcutaneous muscle of Bourgelat. 

 (Nasalis brevis labii superioris Percivall.) 



Girard has described, by the above name, a small, thick, and short 

 muscular fasciculus which covers the external process of the premaxillary 

 bone, and whose fibres, either originating from that, the supermaxillary 

 bone, or the internal face of the supernaso-labialis muscle, terminate in the 

 skin of the false nostril, and the appendix of the inferior tnrbinated bone. 



Rigot has attached to this muscle that described by Bourgelat as the 

 short muscle. The latter is composed of short, transverse fibres, applied to 

 the expansion of the cartilaginous septum of the nose which projects 

 laterally beyond the nasal spine. These fibres abut, by their most eccentric 

 extremities, against the skin of the false nostril and the appendix of the 

 superior turbinated bone. 



In adopting Bigot's description, it is found that the small supermaxillo- 

 nasalis is composed of two portions, which border the re-entering angle 

 formed by the large process of the premaxillary bone and the nasal spine. 

 These two portions, posterior and anterior, unite at their upper extremities. 

 The first appears to be confounded, below, with the middle anterior 

 (depressor alas nasi), the second is continuous with the transversalis nasi. 

 When they contract, they concur in the dilatation of the false nostril and 

 the proper nasal cavity. 



9. Transversalis Nasi. 

 Synonym. (Dilatator naris anterior Percivall) 



A single, short, and quadrilateral muscle, flattened before and behind, 

 applied to the widened portion of the nasal cartilages, and composed of 

 transverse fibres proceeding from one cartilage to the other. Covered by the 

 skin and the aponeurotic expansion of the two elevator muscles of the upper 

 lip, the transverse muscle of the nose covers the cartilages to which it is 

 attached, and is confounded below with the orbicularis of the lips. 



Designed to bring together the internal alas of the nose, this muscle 

 ought to be considered more particularly as the dilator of the nostrils. 



