378 
MR. W. K. PARKER ON THE SKELETON 
the “prepalatine” horns (pr.pa.), and where they unite in front there is a wedge of 
soft cartilage ; also the inner edge of the basal cartilage (iv .) behind, under the hind¬ 
brain, is soft. As to the lateral bars, the eye seizes upon a landmark; this is the 
“subocular fenestra” ( s.o.f, !), very familiar to us in the skulls of Tadpoles. Inside 
this very limited reniform membranous space the bar is purely trabecular. In front 
of it it is palato-trabecular (pa., tv.). Another familiar part can now be seen; it is 
behind the fenestra, and is composed of soft cartilage ; this short tract is the pedicle 
( pel .), for it answers to the dorsal end of the great “ suspensorium ” or palato-quadrate 
of the Tadpole, a part always developed continuously with the basis cranii in the 
Anura. (See “ Batrachian Skull,” Part II., Phil. Trans., 1876, Plate 35, figs. 1-5, pd). 
An oblique soft tract may be seen in front of the subocular fenestra in Myxine ; this 
marks the junction of the pterygo-quadrate region with the palatine. The pre¬ 
palatine horns ( pr.pa .) remain soft; they are large, rounded, and suddenly apiculated 
near their end. Now, for a while, the Tadpole’s skull will fail us in our interpretation; 
as long as I kept, slavishly, to that chondrocranium, as my key to the skull of the 
Marsipobranchs, I was always falling into confusion. The Tadpole’s skull, however, 
just when transformation is taking place, and the skull of the suctorial larva of 
Lepidosteus, greatly enlighten us at this point. (See “ Skull of Batrachia,” Part III., 
Plate 4, figs. 5-9, and “ Skull of Lepidosteus,” Phil. Trans., 1882, Plate 30, figs. 3, 7, 8.) 
Here we have to be cautious; for Myxine has its quadrate region suppressed at the 
part where the condyle is formed in the higher kinds, and there are no Meckelian or 
mandibular rods. Hence that huge, broad, condyle-bearing part of the enormous 
suspensorium of the Tadpole shown in so many of my figures, and often running up to 
the front of the face, is not present in Myxine. Moreover, I am quite persuaded that 
the rudiment of the quadrate region (q.) which does exist, is not in front, but directly 
below the pedicle (pd.), a position which is only slowly gained in the Tadpole; in 
Lepidosteus it is not far in front of the pedicle, being opposite the pituitary body 
(“ Skull of Lepidosteus ,” Plate 30, fig. 3, py., q.c.). 
The remarkable position of the distal part of the “ pier ” (or suspensorium) of the 
mandible in the Tadpole is quite unique ; it exists nowhere else but in the Anura, 
and depends upon the compromise, so to speak, which in them is made between a 
jaw-less and a jaw-bearing type. I must return to the arrested jaw-pier and its 
connexions with the rest of the facial basket-work, when the rest of the cranium has 
been described. 
In the Tadpole the trabeculae, after a time, become united together beneath the fore 
brain by a thin lamina of cartilage, the soft tissue gradually becoming cartilaginous; 
but this posterior intertrabecular tract is not found as a distinct sheet of cartilage. 
Afterwards, when the trabeculae of the Tadpole have united in the ethmoidal region, 
a crest of cartilage appears upon it, which becomes the vertical ethmoid and septum 
nasi in one high tract (“ Batrachia,” Part III., Plate 2, fig. 1). In the Green Turtle, 
I have shown that the intertrabecular cartilage is found as a rounded rod between 
