Hector. — On the Fossil Reptilia of New Zealand. 337 



Not having examined the Anauri district, where the best sections of the 

 formation containing Reptilian remains are exposed, I will not, at present, 

 discuss their stratigraphical position, but refer to the reports of Dr. Haast and 

 Captain Hutton, already quoted. That they belong to the upper part of the 

 mesozoic period, representing the horizon of the cretaceous period of Europe, is 

 rendered pretty certain by the associated fossils, which belong to the following 

 genera : — 



Ammonites, Scaphiies, Nautilus, Belemnites (three species). 



Turbo, Neptunoea, Aporrhais, Conchothyra, Scalaria, Natica, Pleurotoma, 



Dentalium. 

 Terebratula. 



Panopcea, Cytherea, Lucina, Eriphylla, Protocardium, Crassatella, Astarte, 



Crenella, Myacites ? Trigonia (three species), Gucullcea, Axincea, Leda, 



Pecten, Radula, Plagiostoma, Inocera/mus (four species), Mytilus, 



Chama, Gryphcea, Ostrea, Aucella. 



Teredo, Pentacrinus, Corallines, Foraminifera, fish teeth and scales. 



"With the view of assisting collectors in determining the portions of 



Reptilian remains which are most likely to be found, I offer the following 



artificial diognoses of the genera in which they have been provisionally placed : — 



SAUROPTERYGIA. 

 Vertebrce with both ends flat, or concave. 



Teeth curved, with striated, sharp-pointed crowns ; a/re found in the rock 

 matrix free from the jaws. 



A — Plesiosaurus. 



Centrum of dorsal vertebrce short as compared with its width, which is 

 greater tlian its height ; flat, or only slightly concave at both ends. Humerus 

 prismatic, with a round jiToximal surface ; distal end expanded and flat. 



B POLYCOTYLUS, 



Centrum pf dorsal vertebrae, nearly equal in length to its diameter, 

 constricted, articular surfaces circular, concave, with an elongated tubercle in the 

 centre of the depression. Humerus slender and long in proportion to the size 

 of the vertebrce, with two articular facets on the proximal end. 



C — Mauisaurus. 



Centrum of dorsal vertebrce equal in length to the diameter, with smooth, 

 concave sides, and an inferior mesial ridge ; articular facets circular, flat, with 

 a deep pyit in the centre. Humerus with a large tuberosity. 



D — Ichthyosaurus . 



Vertebrce consist of deeply biconcave disks. 



a2 



