1862.] ’ OF LEPIDOSIREN ANNECTENS. 131 
extending as far back as the occiput is certainly not much more 
astonishing than that the frontals should do so, Anyhow, this sin- 
gular disposition of parts is altogether unique; but in determining 
these elements to be frontals I am again guided by the centres of 
ossification, and especially also by the relative position of the bases 
of the bones. In this situation it will be noticed that they are con- 
joined in the middle line, whilst their lateral margins in front are 
directed at first outwards so as to form the upper part of the incom- 
plete orbital ring. Viewed as a whole, these bones have been justly 
compared to a pair of horns ; and their presence, more than any other 
of the osseous elements, imparts to the skull its unique character. 
It should be mentioned that the under surface of each bone presents 
near the inner border a well-defined longitudinal ridge, evidently for 
the firm attachment of the masseto-temporal muscles. 
Immediately in front of the foregoing, there occurs a solitary bone 
having the form of an isosceles triangle, whose base is connected by 
ligaments with the anterior margin of the combined frontals. This 
bone (K, figs. 1, 3) is regarded by Natterer and Bischoff as the repre- 
sentative of the intermaxillary—their opinion being grounded on the 
circumstance of its supporting a pair of incisive teeth (L) at its ante- 
rior inferior surface. It is impossible, perhaps, to speak confidently 
on this point ; but I may observe that the teeth in question are not 
actually implanted in this bone, but are moveably connected with it 
by ligamentous substance. I regard this fibrous matrix as homolo- 
gous with the absent incisive elements (or intermaxillaries); whilst 
the triangular bone from which the teeth depend is the conjoined 
nasals. I find no trace of the transverse suture described by Bischoff 
as occurring in Lepidosiren paradora ; but the tip of the bone in 
front and above is marked by a well-defined oval surface, roughened 
for the attachment of the thick cranial fascia. 
Below the above we find a remarkable bone, which, at first sight, 
appears to be the upper jaw (M). Functionally, indeed, as acting 
in antagonism with the lower jaw, it may be so regarded ; but mor- 
phologically and homologically it is clearly referable to the associated 
palatine bones, which are here of enormous size, intimately blended 
in front, and widely separated behind. Either division is extended 
in front so as to form three tooth-like projections, each of which is 
protected by a thick coating of enamel, the whole constituting a 
dental apparatus of the most formidable character. In the closed 
condition of the mouth these teeth become dove-tailed with the 
interspaces resulting from the similarly formed dentition of the jaw 
properly so called, the anterior palatine tooth-processes being then 
placed anterior to the corresponding dentations of the lower jaw. 
This arrangement is very peculiar ; and its singularity is not lessened 
by the circumstance that the incisive teeth, above alluded to, have 
no antagonists. The true maxillary bones have no existence—a defect 
which, as Miiller and Bischoff observe, also obtains in Proteus. The 
lip-cartilages, described by the latter author as occurring in L. para- 
dowa, I have not found to be present in this species. 
The jaw proper (N) consists of several elements, as in reptiles 
