48 



THE EXTINCT BATBACHIA, BEPTILIA 



The end of tlic muzzle was broken from a part or the whole of the cranium, which lias not been rediscovered, 

 though Dr. Turner has made careful search, It was found in front of the vertebrae here regarded as cervical, at some 

 distanec from them. 



The whole skeleton has been under considerable pressure, so that most, of the ribs have been pressed flat on the 

 vertebrae; the long parapophyses of the cervicals bave most of them been fractured at their bases and compressed, 

 those of opposite sides thus approaching more nearly in the form of chevron hones than they otherwise would bave 

 done. The proximal cervicals are obliquely flattened by the pressure; the other oervicals have the bodies naturally 

 flat, with the articular surfaces much less so than the median portion. Some of the caudals arc obliquely distorted. 



Description — Vertebrm. — The neck may be safely assumed as a point of departure, as it consists of above sixty 

 mostly continuous vertebras, which graduate to an atlas of very slender proportions. Most of them preserve more or 

 less developed parapophyses. At the posterior extremity of this series, Bixteen are perfectly continuous, and in this 



portion a great gradation in form is apparent. The anterior are narrow, compressed, and similar to the more distal 

 cervicals in the elevated position of the lateral angle; the anterior are subquadrate, thick, and with lower lateral rib, 

 and stronger ?pleurapophysis. In these respects the latter resemble the dorsals which follow, towards what r believe 

 to be the tail. Pour anterior dorsals are in one mass (figured in plate 8); in this series the lateral angle first approach- 

 ing, is Anally lost in the margin of the rib-pit, the posterior thus resembling other dorsals. There can be SO far little 

 doubt that the anterior and posterior extremities of the masses are correctly interpreted. 



In a series of four anterior dorsals, which like the preceding, are in their original continuous mass, those of one 

 cxtremil v have, centra rounded in section, with inferior rib-pits; those of the other have quadrate contra and elevated 

 diapophyses; the former liavo the character of the first dorsals, the latter of the median dorsals. The posterior dor- 

 sals and anterior caudals form in like maimer a continuous series of eleven vertebras, fractured in four places. In 

 them the diapophyses steadily descend, reaching the inferior plane in the last, thus with the reduction of the venous 

 foramina to one, at the seventh, indicating the point of transition from dorsal to caudal series. The zygapophyses 

 preserve the usual arrangement, but are much compressed, so that the posterior or down-looking, are confluent, and 

 scarcely separated by an emargination. 



The neural spines at their bases have a slight posterior obliquity, and the superior portion leans strongly in the 

 anterior direction. The Inferior limbs of the cervical pleurapophyses appear to be entirely wanting. The articular 



fiecs for the chevron bones are seen at the extremity of the inferior rib of the caudal. 



Of the cervicals there are both axis and atlas. Of the caudals, probably the distal half, at least, is lost. A single 



vertebra near the middle does not relate to cither of those anterior or posterior to it. There are, therefore, at least, 

 four lost from that region also. 



There is a considerable interruption immediately anterior to the last, dorsal vertebra. Three large vertebrae, with 

 long diapophyses, belonging here, were imbedded in tin', hard matrix which protected the pelvic, arch. These 

 an; far from relating immediately to the vertebrae preserved before and behind them. I estimate the number missing 

 US follows: Seven of the fourteen dorsals preserved have more or less elongate diapophyses. In the I'lesiosauri. 

 vertebra; of this character, are much more numerous; in P. homalospondylus Owen gives seventeen. If we add 

 ten to the series in the present species it will give the abdominal space between the adjacent margins of the o. 0. pubis 

 and coracoidea an extent equal to the length of the pelvic arch. This is relatively shorter than in the Plesiosauri. 

 Dr. Turner found that a space of " three or four" feet intervened between the two portions of the skeleton, which was 

 otherwise continuous. I think ten an average number to represent safely the missing dorsals. 



Prom the cervical proximal regions probably three vertebrae are missing from two interruptions. The remainder 

 of the cervical Scries exhibits three interruptions. Most of the proximals have been broken medially, leaving the 

 ticulations solid, an advantage in determining their continuity. Three vertebras and one-half are thus found to he 

 missing in this region. 



The whole number of vertebra; preserved and lost, with the relative lengths of each, maybe stated as follows: 



