270 SQXJAMATA, 



Body much elongated. Premaxillse not produced into a rostrum* 

 Teeth slightly compressed, acute, curved, often carinated and grooved. 

 Vertebrae without, or with rudimental zygosphenal articulations, and 

 strong zygapophyses ; chevrons free. Humerus short and broad. 

 The skull is represented in fig. 59. The so-called Taniwhasaurus 

 presents no characters by which it can be distinguished from the 



Fig. 59. 



Platecarpus curtirostris, Cope. — Frontal aspect of the cranium ; from the Upper 

 Cretaceous of N. America. Greatly reduced, pmx, premaxilla ; mx, 

 maxilla ; fr, frontal ; prf, prefrontal. (After Cope.) 



present genus. The limb-bone from the Cambridge Greensand 

 described by Seeley r as Cetarthrosaurus may indicate a closely 

 allied form 2 . All the species are of medium or small size. 



Platecarpus oweni (Hector 3 ). 

 Syn. Taniwhasaurus oiveni, Hector 4 . 



The type of Taniwhasaurus ; imperfectly known. The crowns of 

 the teeth measure 0,025 in height and have a basal diameter of 

 0,013; they are grooved, but not distinctly faceted, and with 

 obscure carinse. 



Hah. New Zealand. 



The following specimens, unless it is stated to the contrary, are 

 from the Cretaceous of Amuri Bluff, South Island, and were 

 obtained in 1880 by exchange with the Trustees of the Colonial 

 Museum, Wellington. 



R. 876. A tooth in matrix which agrees with the description of 

 those of the type specimen; from the Cretaceous of 

 Waipara, Canterbury, New Zealand. 



Presented by Sir E. Owen, K.C.B., 1884. 



1 Quart. Journ. Geol. Soc. vol.xxix. p. 505 (1873). 



2 See Hulke, Proc. Geol. Soc. 1883, p. 50. 



3 Trans. N. Zealand Inst. vol. vi. p. 353 (1874).— Taniwhasaurus. 



4 Loc. cit. 



