204 PEOP. W. K. PARKER ON THE STRUCTURE AND 



As a Urodele, we shall see in the next stage (PL XLI.) that this species becomes a 

 culminating type ; as a Vertebrate it, in a sense, stands still, and even recedes ; we 

 must find another " sucker " before we shall see the blossoming of any thing more 

 perfect than the Menopome and the great Salamander show. 



The Skull of the adult Triton cristatus. 



A. Investing Bones. 



The main part of the Newt's skull is nearly oblong, the sides only converging gently 

 from behind forwards ; a line drawn completely round it would be a very regular 

 ovoid, the fore half a semiellipse, the hind half a semicircle. 



The parietals and frontals (PI. XLI. fig. \, p,f) are large, dense, and permanently 

 distinct ; and the teeth of the sutures are few and very large. The sinuous hind margin of 

 the dilated temporal part of the parietals does not hide the supraoccipital synchondrosis, 

 nor cover the posterior canals (p.s.c). Each temporal wing has its sinuous outer 

 margin parallel with the axis, and separated from the orbital part by a gently concave 

 space. 



There are four or five large sutural teeth on each side, strongly interlocked ; and the 

 fore mai'gin of the parietals is hidden by the large " teeth " of the squamous coronal 

 suture. 



The frontals (/) have only two definite teeth, right and left, along the frontal 

 suture; these bones are gently convex, oblong, and, in turn, covered by the "teeth" of 

 the overlapping nasals. 



The parietals and frontals (fig. 3, ;p,f) have a moderate orbital downgrowth, equal to 

 the sphenethmoidal wall (sp.e). The nasals («) are oblong, and are separated by the 

 grooved nasal process of the premaxillary {n. ])x) ; their upper surface is convex and 

 rugous, their edges dentate ; the fore margin is obliquely notched, to make space 

 antero-laterally for the nasal roof and apertures [na, e. n). 



The squamosal [sq] is a strong wedge of bone ; it articulates above and behind with 

 the posterior angle of the parietal, bites into the top of the auditory capsule, has a 

 transverse subapical ridge, which sends down from its middle a short crest and a nail- 

 like preopercidar process, which, in turn, binds down on tlie suspensorium as it runs 

 downwards, outwards, and forwards ; it overlies the edge of the suspensorium. 



Outside the junction of the nasals and frontals there is a supero-lateral bone, the 

 outer ethmoidal or prefrontal {p.f) ; it is subtriangular and convex, and is wedged in 

 between the upper bones and the maxillary beneath (fig. -3, p.f) ; the prefrontal is 

 perforated and grooved for the nerves and vessels of the fore face. The whole margin 

 of the premaxillary {px) is now only three fifths as long as that of each maxillary 

 {mx) ; its palatal face has a considerable breadth behind the marginal belt ; its sides 

 are sutured to the maxiUaries, and its concave hind margin to the vomers (fig. 2, v). 



