154 



MEMOIRS OF THE UNIVERSITY OF CALIFORNIA. 



margin. There is no ridge on the inferior face of the centra. The diapophy- 



ses and parapophyses are large and are nearly in contact on the specimens 



described. 



Of this species there was originally described a small amount of material 



representing vertebrae, ribs, a portion of a scapula, and a femur. Other ma- 

 terial originally described under the name Ifacln't irnm />t'll(i/i 

 has recently been referred by San va go (1903) to/. (?) rhcti- 

 citH. Von Huene (1902, p. 71) has suggested that liachi- 

 trema is an ichthyosaurian rather than a dinosaur. 



The material which has been referred to /.(?) rltetiens 

 and to RacMtrema pellati by Sauvage, and was figured by 

 him (1883), appears to represent an iehthyosaurian having 

 its closest affinities with the Ichthyosaurinae. The vertebra 

 of /.( ?) rheticus figured by Sauvage (1883, pi. 8, fig. 4o) evi- 

 dently represents a middle dorsal in which the diapophyses 

 are almost in contact with the large parapophyses (fig. 154). 

 In no representative of the shastasaurine group are parapo- 

 154. ichthyoxau- phvses known behind the region in which the diapophysial 



nw(?) ructions. Sao- ' J . 



vage. Outline, side articular races become separated irom the neurapophysial 



sal' vertebral e cen- 

 trum, 



duced. 



from 



rp - 



(A A a pt e d 



faces. The upper arch referred to RacMtrema jtrllut i is how- 

 ever somewhat more primitive in its characters than the cor- 



responding arches of the Jurassic ichthyosaurs. 



ICHTHYOSAURUS (?) HECTORI Lydekker. 



Ichthyosaurus aitstralis Hector, Trans. New Zealand Inst., vol. (5, p. .'{;">. 

 Ichthyosaurus lectori Lydekker, Catlg:. Foss. Kept. Brit. Mus., pt. 2, p. ll:i. 



In the collections of fossil reptilia of New Zealand examined by Hector, the 

 genus Ichthyosaurus was represented by a single vertebral centrum, in a mica- 

 ceous sandstone from the rocks of Mount Potts, in the Rangitata district of the 

 province of Canterbury. The beds were said to be identical with strata that 

 in other parts of the colony were considered to be Triassic. 



The name /. australis, which Hector first used for this form, having been 

 used for a Cretaceous species from Australia, Lydekker named the species 

 after Hector. 



So little is known of this form that no suggestion regarding its affinities 

 can be made. 



ICHTHYOSAURUS, sp. 



To this genus there have been referred a number of ichthyosaurian remains 

 obtained in Rhaetic beds at Aust Cliff near Bristol, England. This material 



