186 PEOF. W. K. PAEKEE ON THE MOEPHOLOGT 



laryngeal patches (Ix) are quite similar. Altogether the skulls of Cynops and of Notoph- 

 thalmus are only unlike in non-essentials. 



A considerable number of the Caducibranchs agree with each other in all that is 

 essential in their skulls ; but others show remarkable modifications, as I shall soon 

 show. 



Species 4. — Skull of Taricha torosa (adult). North America. 



This skull is only two thirds the size of the last ; it is flatter and feebler, but agrees in 

 all essentials with the stronger specimen. The cartilaginous basi- and supraoccipital 

 regions (PL XIX. figs. 4, 5, s.o,f.m) are wider, in conformity with the less intense ossi- 

 fication of the skull generally. 



The occipital condyles (oc.c) are distinctly pedunculated, as a correlate of the deep 

 odontoid notch ; they look a little inwards and downwards, but most backwards. 



The auditory masses are one continuous bone on each side with the occipital moiety ; 

 they look forwards and outwards, and the general outline behind is crescentic, not 

 straight, as in Cynops. The semicircular canals are strongly marked on the huge ovoidal 

 ear-masses (fig. 4) ; below, the fenestra ovalis is largely surrounded by unossified carti- 

 lage ; and the oval stapes (st) is also soft. Above, there is a fissure in the prootic tilled 

 by cartilage ; this is continuous with the facet to which the pedicle is attached, as in 

 the adult Frog. Here, outside the hole for the facial nerve (7), the prootic itself forms 

 a sheath to the raised facet for the pedicle (pd), which is hidden by the rim of the 

 pterygoid (pg). 



Prom the middle of the optic passage (2) to the foramen ovale (5) there is a carti- 

 laginous (alisphenoidal) tract, and then the sphenethmoid (sp.e) runs nearly to the curved 

 ethmopalatine (e.pa). 



The nasal capsules (na) are entirely unossified ; the external nares (e.n) are small and 

 round, the internal nostrils arc large (fig. 5, i.n). The internasal lamina can be seen both 

 above and below (figs. 4 & 5), forming the hinder boundary of the internasal recess (m.n.p). 



There is a strong quadrate bone (q) in the suspensorium. The condyle looks forward, 

 as in the last two kinds. The fore part of the suspensorium. gives off a long pterygoid 

 process, which is longer than the pterygoid bone ; from its base upwards the suspensorium 

 is unossified, its pedicle being closely locked within the pterygoid. This species has the 

 condyle of the pedicle most like that of a Prog. Prom the rim of this joint the ptery- 

 goid bone runs inside the quadrate, wedge-like, and then forwards, supporting the 

 counterpart cartilage ; the latter touches the zygomatic process of the maxillary (mx), 

 but the apex of the bone docs not. The falcate palatines (fig. 5, pa) are imbricated 

 beneath the vomers (v), and the convex edge is not a sharp blade, but a saw, the teeth 

 being uniserial and inturned (on the right side of fig. 5 the palatine is represented as 

 absent). The concave back of this little saw corresponds with the outer edge of the 

 parasphenoid (pa.s). 



The hard palate is not so well developed as in the last two kinds. The vomers (fig. 5, 

 v) are rough miniatures of a pruning-hook, the semicircular notch margining the inner 

 nostril (i.n). The convex back of the hook is articulated by suture to the palatine plates 



