352 Transactions. — Geology. 



Both jaws are prolonged as blnnt processes for 2 inches beyond the tooth 

 series, and show no sign of terminal teeth. The height of the lower jaw at 

 first tooth is 2-5 inches, and at the tenth tooth 3 '5 ; and the njDper jaw appeared 

 to maintain its width in the same remarkable way. 



iSTo. 10 d. — A string of 10 lumbar vertebrae, from the Waipara, appear also 

 to belong to this genus. They are procoelian and subprismatic in section. 

 The neural spines are not well preserved, but were attached along the whole 

 length of the vertebrse. The lateral processes {inleurajyoi^liyses) are short stout 

 cylindrical tubercles, 1*5 inches long by 1*3 inches in diameter, with rounded 

 extremities, received into distinct articular surfaces on the heads of the ribs. 

 The surface of the bodies of the vertebrae is roughened and striated. They 

 slightly expand towards both articular extremities, therein differing from 

 another genus to be described. The articular surfaces are smooth, and the 

 posterior extremity is marked by the peculiar epiphysial ridge shown in the 

 drawing of Mosasaurus vertebrae in Mantell's " Fossils of Sussex." 



The neural spines are remarkable for their great breadth, being 2*5 inches 

 long and 3 inches high, and also for the very strongly striated surface, which 

 character appears to be common to nearly all the flat bones of this reptile. 



The dimensions of the vertebrae are : — 



Inches. 



Transverse ... ... ... ... ... 3*5 



Height ... ... ... ... ... 3 



Length ... ... ... ... ... 3*5 



No. 10 e. — I refer to this species 7 ribs, which are flattened and channelled 

 deeply on the internal surface, and very much expanded towards the head, 

 where they have w^ell-developed articular processes, which are irregularly 

 cup-shaped, with thin margins. They taper very much in the other direction. 



Longest rib, of which there are 8, is 18 inches; also two abdominal ribs 

 aftd three phalanges. 



These were found in a slab at the Waipara, close to the vertebrae (10 d), 

 and the evidence for connecting them with this genus is afforded by the 

 peculiarly-excavated form of the head of the rib, which appears to tit the 

 articulated surface on the tubercle, and also their striated surface ; and, further, 

 certain fragments of spinous processes intermixed with the ribs also assist in 

 this determination. 



No. lOy. — Three caudal vertebrae, from the Amuri Bluff, evidently belong 

 to the same species with the above, and form one of the most important 

 links in connecting palaeontologically these widely-separated localities. 



No. 10^^. — A slab of 20 caudal vertebra3, chevron processes, and neural 

 spines, which also belong to this species. Obtained from the base of the 

 boulder bed at the Amuri. 



The most anterior vertebra is 2*3 inches in diameter, whilst the last 



