626 
DE. G-UNTHEE ON THE ANATOM ST OF HATTEEIA. 
Suborder A. Ainphisb ce, noidea. Vertebrae procoelian. No posterior orbital ring or 
temporal bar ; no columella. 
Suborder B. Cionocrania. Vertebrae procoelian. An orbital ring with a temporal 
bar more or less complete. Columella present. 
Suborder C. Chamceleonoidea. Vertebrae procoelian ; a bar crossing from the pa- 
rietal to the mastoid ; temporal bar complete. No columella. 
Suborder D. Nyctisaura. Vertebrae amphiccelian ; orbital ring and temporal bars 
not developed. A columella. 
Third order : RhynchocepJialia *. Quadrate bone suturally and immoveably united with 
the skull and pterygoid ; columella present. Parts of the ali- and orbito-sphe- 
noid regions fibro-cartilaginous ; rami of the mandible united by a short fibrous 
ligament. Temporal region with two horizontal bars. Vertebrae amphiccelian. 
Copulatory organs none. 
II. Loricata. Anal cleft longitudinal ; copulatory organ simple. Anterior ribs bifur- 
cate; sacral vertebrae two. 
Fourth order : Crocodilia. Quadrate bone suturally united with the skull ; parts of 
the ali- and orbito-sphenoid regions fibro-cartilaginous; rami of the mandible 
united by suture. Choanae formed by pterygoid and palatine bones. 
III. Cataphracta. Anal cleft longitudinal ; copulatory organ simple. Trunk-ribs and 
sternum dilated, more or less completely united by suture. 
Fifth order : Chelonia. 
The skeleton of Hatteria — with its amphiccelian vertebrae and abdominal sternum on 
the one hand, and its highly developed osseous skull and uncinate apophyses of the ribs 
on the other — presents a strange combination of elements of high and low organization; 
and this is the more significant as this peculiar animal occurs in a part of the globe 
remarkable for the low and scanty development of Reptilian life. The New Zealand 
of the present period is inhabited by only a few (about nine) small species of the cosmo- 
politan Geckos and Skinks and by a single species of frog ; and it is not probable that 
this small list will be considerably increased by future researches. With more con- 
fidence may we look forward to discoveries of remains of extinct forms, of which one 
Plesiosaurus only, the Plesiosaurus australis of Owen, is known at present ; but whether 
they will be of such a nature as to afford a better insight into the history of develop- 
ment of the Rhynchocephalian type, whether they will show that Hatteria was at one 
time not its only representative, and whether such evidence will be found in New 
Zealand at all, the future must decide. 
* In this way the name Bhynchocejohalus may be preserved, which, otherwise, must give way to the prior 
Hatteria. 
