62 THE SALAMANDER 



against the pre-vomerine teeth, and thus assist in working the food 



backwards to the pharynx so that it can be swallowed. 



The whole operation is performed with lightning-like rapidity, 

 but the action is easily observed in the living animal by putting it 

 in a glass receptacle, and allowing a small worm or slug to crawl 

 down the side. In snapping at it the Salamander not infrequently 

 gets its jaws momentarily wedged open against the glass with the 

 tongue protruded, so that its action may be seen. 



It will have been noticed that the Salamander uses a very different 

 method in securing its food from that of the Frog. In the latter 

 animal the tongue is freely mobile, and it is this organ alone which 

 is extruded, the skeleton of the hyoid taking but little part in the 

 operation. In the Salamander, on the other hand, the tongue is 

 securely fixed to the floor of the mouth, so that its movement carries 

 with it the whole mouth floor and the hyobranchial skeleton as well, 



M. cephalo-dorso-subpharyngeus (mihi)^ (m.c.ph.). 



Dorso-trachealis .... Fischer (1843); Osawa (1902). 



Constrictor pharyngis Mivart (1869). 



Cephalo-dorso-pharyngeus ..... Druner (1901). 



This is a compound muscle formed from the M. transversalis ven- 

 tralis iv and the MM. levatores arcuum branchiarum iii and iv of the 

 larva (PI. XXIII, fig. 77). 



It arises dorsally by two heads, the anterior arising — together with 

 the anterior part of the M. cucuUaris — from the crista muscularis^ a 

 ridge formed by the squamosal above the ear capsule. The posterior 

 head arises from t\\c fascia dorsalis together with the posterior portion 

 of the M. cucullaris and the M. depressor mandibulae, and lies deep 

 to the latter muscle, between it and the M. cucullaris. The direction 

 of the anterior fibres is obliquely postero-ventral, while the posterior 

 ones pass ventralwards practically at right angles to their origin, so 

 that the whole muscle forms roughly a right-angled triangle of which 

 the origin is the base and the anterior edge the hypotenuse. The 

 ultimate insertion of the whole muscle is a very strong fibrous tendon, 

 firmly attached in the middle line dorsally to the pharynx, just in 

 front of the larynx, and ventrally to the truncus arteriosus. A short 

 distance on either side of this median tendon is another tendinous 

 inscription dividing the muscle into two portions, namely, a -pars 

 subpharyngea (pars ventralis, Druner) and a pars dorsalis (Druner), 

 the former lying mesial and the latter lateral to the inscription. A 

 comparison with the larva shows that the pars subpharyngea is the 

 ' This name has been adopted in consultation with Dr. F. H. Edgeworth. 



