n 4 NATURAL SCIENCE. Feb., 



very strongly arched so as to bring the head almost into contact with 

 the back of the animal in the region of the thorax. It is difficult to 

 make these measurements accurately in either the specimen or the 

 photograph, but the discrepancy between the two measurements is 

 too great to be accounted for by this difficulty, and I suspect that 

 Professor Dames' measurements have been made along the inner 

 curve — i.e., through the neural spines — while mine were made near 

 the ventral curve, i.e., through the centra of the vertebrae. I 

 suspect, therefore, that when the animal's neck was straightened out 

 it would be 75 mm. long in addition to the length of the atlas, 

 which may be taken to be a very small quantity as in modern 

 birds. Of the nine cervical vertebrae the middle ones are longer 

 than those nearer the ends of the neck, the fifth being the 

 longest. 



Cervical ribs, apparently movably articulated, may be made 

 out, and there appear to be eight pairs of them. The neural arches 

 and spines are well-developed and strong, the spines being 2 to 3 mm. 

 high. 



The trunk vertebrae being somewhat displaced, and the vertebral 

 column distorted, it is not very easy to make sure of their number. 

 There appear, however, to be ten, measuring together about 70 mm. 

 The vertebrae appear to be almost equal in size, and nine of them 

 bear ribs. There are also ventral ribs, resembling the " abdominal " 

 ribs of the geckos and chamaeleons, and clearly showing the ventral 

 boundary of the abdominal cavity (see 14 in Plate). 



The sacrum is hidden in the Berlin specimen except at its 

 ends. It measures 26 mm. in length. It is probable that there are 

 about seven sacral vertebrae. 



The vertebrae of the tail, twenty in number, measure to- 

 gether about 170 mm.— slightly less perhaps. The first few are 

 very short and stout, each measuring about 4 mm. in length and 

 4 mm. in height. The first four have well developed transverse 

 processes ; in the fifth this process is not well preserved, and the 

 vertebrae behind this have no transverse processes, but only a ridge. 

 The vertebrae are longest nearer the middle of the tail, the eleventh 

 measuring nearly 12 mm. The tail as a whole seems to have had 

 little flexibility, for it is almost perfectly straight in both specimens. 

 The tail of the London specimen has apparently only eighteen 

 vertebrae and measures 180 mm. 



The skull has been much further exposed since the photograph 

 was taken. It is large and fairly massive, the jaws are stout, and 

 teeth are very easily made out in the upper jaw. Those of the lower 

 jaw are, however, hidden by those of the upper, and it is impossible to 

 say at present how many there were (see Fig. i). The sclerotics are 

 ossified. The hinder part of the skull is destroyed in the Berlin 

 specimen, and it is worthy of note that the cranial cavity was not filled 

 with matrix. No part of the skull is recognisable with certainty in 



