296 REPORTS ON THE STATE OF SCIENCE, 



inaxilla is a stout, deep, and smooth laminar bone, but its thin oral 

 border has not hitherto been sufficiently well seen to determine whether or 

 not it was toothed. The palate (Pla.te II., iig. 1) is only partially known 

 from the two specimens in the British Museum noticed by Huxley (4). 

 The pterygoids (pt.) are long and narrow stout bars, each evidently 

 extending outwards behind in a deep lamina for union with the quadrate, 

 and apposed to the basi-pterygoid process of the basi-sphenoid with a 

 relatively large wing. A pair of short longitudinal ridges, which extend 

 along the bone immediately in front of the last-mentioned wing, seem to 

 bear stumpy teeth. The interpterygoid vacuity (ipt.) is very long and 

 narrow, extending further forwards than in Sphenodoji. The palatine 

 (/>/.) is also long and narrow, forming a single sharp longitudinal ridge, 

 which bears one row of stumpy teeth, evidently opposed to the inner side 

 of the mandibular dentition. The vomerine region is unknown. 



The mandible is best shown in the specimens described by Owen 

 (S. Nos. 1, 3). It is peculiar in exhibiting no prominent coronoid 

 process, and there is no lateral vacuity. The symphysis is short and 

 bluntly pointed, only the extreme end being in contact with the down- 

 wardly curved beak. The splenial enters the symphysis and is conspicuous 

 when viewed from below, where it forms the lower edge of the anterior 

 part of each mandibular ramus. The dentary bears a single row of 

 stumpy teeth, as imperfectly shown in B.M. No. R. 1236. The sur- 

 angular (named coronoid by Owen) is relatively large, but scarcely rises 

 higher than the posterior end of the dentary. The hinder end of the 

 articular, posterior to the glenoid cavity for the upper jaw, has not been 

 clearly observed. 



Vertebral Column. — The vertebras are so delicate and fragile tliat 

 tiiey are rarely well preserved. All are characterised by a very large 

 neural canal and also by a comparatively small, elongated and constricted 

 centrum, which is deeply concave at eacli end. No intercentra have 

 been observed even in specimens which seem to be sufficiently clear to 

 show them if these elements were present. The number of vertebrixj is 

 uncertain in all regions, but in S. No. 3 there is space for seven or eight 

 cervicals, while in B.M. Nos. R. 1538-39 there seems to be evidence of 

 about 15 rib-bearing trunk vertebra?. The neuial spines in the latter are 

 le.ss elevated than in Sphenodon, Imt not thickened at their upper'end. 

 There are remains apparently of long posterior cervical ribs in B.M. No. 

 R. 1239; while the trunk-ribs are large, stout, antero-posteriorly com- 

 pressed, marked by a longitudinal groove on each face, and clearly single- 

 headed (S. No. 4). There are no traces of uncinate processes, The 

 sacrum has not been satisfactorily observed, and only a few of the 

 anterior caudal vertebra; are known (Huxley, 4). As in Sphenodo7i, the 

 neural spines in the anterior caudals are comparatively long and slender, 

 while the chevrons are still longer. 



Fore Limb. — In the pectoral arch the median limb of the interclavicle 

 is relatively long, as in Sphenodon ; but the coracoids seem to have been 

 completely ossiBed, not remaining cartilaginous at the inner liorder as in 

 the existing genu.s. Each coracoid is somewhat longer than broad, and i\. 

 fragmentary example has been figured by Huxley (4, pi. xxvii., fig. 3), 

 who niai'ks a remnant of the anterior border ' cL' but leaves the deter- 

 mination of this piece doulitful. A crushed specimen of the bone was 

 also identified by Owen (1, pi. vi., fig. 9), but he did not recognise the usual 

 o^■al foramen, which is exhibited in all the three known coracoids internal 



