DEVELOPMENT OF THE SKULL TN THE BATRACHIA. 151 



wliat is seen in //. tt'inporalis, where the muzzle is very broad : here the fore and hlud 

 regions are equal, and each is three-fourths the length of the mid skull, which is both 

 long and broad. 



The occipital condyles (Plate 28, figs. 1 and 2, oc.c.) are postero-inferior, and are 

 moderately large. A considerable tract of cartilage remams in both the basi- and 

 superoccipital regions ; there is a triangular endosteal supcroccvpital hone (figs. 1 and 5, 

 s.o.) ; and the bony tracts {pr.o., e.o.) of the same side are quite confluent. Below, the 

 bone leaves an even crescent of cartilage at the margin of the floor of the vestibide 

 {(H(.) ; above, the bone is snagged, and leaves an irregular cartilaginous tegmen (fig. 1). 



I could find no secondary fontanelles, but a very large long main space with no 

 lateral ingrowth for a considerable distance along the sides, quite unlike the next. 

 Mox'eover, this deficiency of the " tegmen cranii" shows itself both behind and before : 

 belund, the roof is devoid of cartilage up to the ear-capsiUes ; and in front the roof 

 extends a very short distance over the hemispheres. As this is a young specimen, 

 the ear-masses and the nasal roofs show much of their primary form ; they are not 

 drawn into new shapes by the overgrowth of the peripheral bones and arches. 



Hence comes the narrowness of the skull in the auditory region, for the tegmen 

 tj'mpani is merely a narrow selvedge to the ovoidal ear-sacs ; this would be at least 

 somewhat modified in an old individual. On tlie whole, the orbital region, or mid- 

 skull, is very Polypedatine, but is broadest behind, narrows gently, and widens out 

 again towards the ethmoidal region. 



What is very remarkable in so young a skull is the trespassing of the so-called 

 "prootic" round the front of the foramen ovale (V.), even so as to include the lesser 

 cranial nerves between it and the foramen opticum (IL). Therefore, so early, the 

 orbital region is half of it bony, the gu'dle-bone {eth.) being as long as the cartilage 

 behind it. It runs into the septum nasi (s.n.) both above and below ; then it takes in all 

 its own cartilage, athwart the ethmoidal " wings ;" above, it scants a httle, and leaves 

 the edge of the ethmoidal roof, at its junction with the nasal roofs (fig. 1), naked. 



These roofs are very large and broad (fig. 1), larger than the floor (fig. 2) ; the inter- 

 trabecular wedge (or ivall) between both grows into a distant " prenasal rostrum" 

 {}^.n.) in front, which is a new thing in an Oi'iental member of this Family. Never- 

 theless, the snout is very broad, and the rostrum, which is drawn as dissected out in 

 the figures, in reality turns downwai-d, as in embryos of all kinds that possess this 

 projecting cai-tilage. In this kind, as in its congeners, the nostrils (e.n.) are very 

 wide apart, nearly as wide as the "choante" or inner openings (fig. 2, /.?;.). The pro- 

 rhinals (p.rh.) and the labials (u.l^.u.l-.) are well developed. 



The arrest of the " parotic wings," in a skull with such long regions, causes the 

 facial "bow" to be strongly bent; otherwise all is normal; the bones (pa., p*/.) are 

 already of the normal size and strength, and leave a cartilaginous palato-suspensoriiJ 

 of the average size. 



The forks of this arch differ greatly, for the pedicle {j^d.) is very short, and tlie 



