624 
DR. GUNTHER ON THE ANATOMY OE HATTERIA. 
the majority of lizards occurs also here, but each centrum is split into two equal halves. 
The property of reproducing lost portions of the tail is indicative of low organization ; 
yet it is evidently much less pronounced in Hatteria than in other lizards of a similarly 
low type. In other respects the vertebral column of Hatteria does not deviate from the 
Lacertian type, such points as the uniform development of strong neural spines, or the 
singularly oblique direction of the caudal pleurapophyses, which point forwards, being 
of minor importance. 
2. The modifications of the costal hsemapophyses : — a , into a series of appendages 
identical in position with the uncinate processes of birds ; and, b, into a double terminal 
series connecting the ribs with the thoracic and abdominal sterna, the distal pieces being 
much dilated to form the base of a system of muscles. 
3. The development of a system of abdominal ribs, neither floating (Crocodile) nor 
mere continuations of the true ribs (Chamseleon), but standing in functional relation to 
the ventral integuments. 
4. The continuity of the ossifications of the coracoid, the presence of an acromial 
tuberosity of the scapula, and the subvertical direction of the os ilium are very remark- 
able deviations from the Lacertian type ; whilst the arrangement of the bones of the 
limbs does not show any peculiarity, except in the articulation of the fibula , which is 
joined to the calcaneum only. 
5. Absence of the pecten of the eye. Entire absence of the tympanic cavity ; attach- 
ment of the hyoid bone to the terminal cartilage of the stapes ; commencement of a 
spiral turn of the cochlea. 
6. Although the details of the structure of the heart are, for the present, unknown, it 
has been ascertained to be of the Lacertian, and not of the Crocodilian type. 
7. The organs of respiration and digestion adhere closely to the Lacertian, and more 
especially to the Agamoid type, as does the greater portion of the uropoetic organs. How- 
ever, the kidneys are entirely within the pelvis ; and the absence of a copulatory organ is 
a character by which Hatteria is distinguished from all other Saurians. 
There can be no doubt that Hatteria must be removed from the family of Agamidce, 
and that it is the type of a distinct group ; but the question is whether this group should 
be subordinated to the Saurians as a family like the Agamidce, Iguanidce, &c., or 
whether the characters pointed out are deemed of sufficient importance to assign to it a 
more distant position from the other Lizards. In a system founded upon external 
characters only, the former course would be taken, and a family Hatteriidce would be 
placed near the Agamidce, with which it agrees in the majority of its external characters. 
However, there is scarcely a systematist of the present day who does not pay more or 
less attention to anatomical characters in establishing the higher divisions. Thus Hr. 
Gray admits into the diagnosis of his section Squamata ( = Lizards and Ophidians) the 
articulation of the tympanic to the skull and the paired copulatory organs as principal 
