208 PROF. W. K. PAKKER ON THE STEUCTUEE AND 



In the old individual which I have been describing, the whole of the second basi- 

 branchial was absorbed ; but in a younger specimen (fig. 7", t.hy) I found a sjiatulate 

 rudiment in front of the larynx {Ix). 



Recapitulation of the Characters of the Skull of the adult Newt. 

 As the Common Newt makes a convenient " norma " as a typical " Caducibranch," 

 the characters of its skull may be profitably reenumerated. 



A. Investing Bones. 



1. The frontals and parietals are distinct, and retain the coarsely dentate frontal 

 coronal and sagittal sutures, as well as the squamous and harmony sutures with the 

 contiguous bones ; each pair of bones forms a subequal square territory. 



2. The nasals are very similar to the main roof-bones, they keep their distinctness 

 from each other and from the neighbouring bones, cover a quadrangular region, and 

 imbricate the frontals as the frontals imbricate the parietals ; the nasals are separated 

 by the nasal process of the premaxillary, as in Birds ; the prefrontals are pyriform 

 shells of bone perforated by the orbito-nasal nerve. 



3. The trowel-shaped squamosals have, as in the Anura, an upper or temporal and a 

 lower or preopercular region ; they articulate, above, with the parietals. 



4. The premaxillary is azygous ; and the maxillaries are subequal : they have ascending 

 and palatine processes ; and the latter are a considerable distance from the quadrate, not 

 joined to it by any intermediate bone, where they end in a jugal process ; they are 

 dentigerous. 



5. The septo-maxillaries are small and seed-shaped. 



6. The dilated vomers are confluent with the long styliform palatines; these carry 

 teeth on their inner edge, each row running submesially (" mecodont ") and on the 

 basis cranii. 



7. The pterygoids are rather small, with a pointed, outturned fore end ; they behave 

 as ectostoses, and do not remain as parostoses like the palatines from which they wei-e 

 segmented. 



8. The parasphenoid is a very large, oblong bone, cochJeate behind, where it has 

 united (on its upper surface) with the bony cephalostyle ; it reaches nearly all the way 

 from the foramen magnum to the middle nasal passage. 



9. Of the bony plates of the mandible the hiudermost of articular is grafted on the 



cartilages ; it is two thirds as long as the ramus ; the splenial is small, and half as long ; 



the dentary large, and runs only a little short of the angle ; both the latter are 



dentigerous. 



B. The Endocranitim. 



10. The hinder and middle parts of the skull are only slightly separated by cartilage; 

 the fore part (ethmonasal) is unossified. 



