224 



DK. EMBLETOX AXD ME. ATTHEY OX THE 



triangular form which is the keystone of the arch, and which in 

 consequence we have called the true supraoccipital : the same 

 arrangement exists in the skulls of Crocodiles and Alligators ; and 

 in these the occipital vertebra so constituted articulates above 

 with the posterior borders of the parietals, and is more or less 

 overhung by them ; but in Loxomma the pair of bones above- 

 mentioned is interposed between the arches of the parietal and 

 occipital vertebras, projecting beyond and overhanging the occi- 

 pital vertebra exactly as the parietal arch does in Crocodiles, etc. 



Is this pair of bones properly designated supraoccipital, though 

 it is actually so in position ? Does it belong at all to the occi- 

 pital or to the parietal vertebra, or is it a pair of dermal bones 

 intercalated between the arches of these two ? If it belong to 

 the occipital, then there are three supraoccipitals ; if to the pa- 

 rietal vertebra, then this must have had four pieces forming its 

 arch. It seems most probable that it belongs to neither, but is 

 a pair of independent pieces like the postorbitals (if these are not 

 merely subdivisions of the postfrontals) and the supratemporals, 

 and, like them, dermal ossifications, and let in, so to speak, be- 

 tween the regular vertebral arches. They cannot be the paroc- 

 cipitals of Professor Owen. 



That 'Loxomma had limbs, probably four, in the form of pad- 

 dles, there can be little doubt ; but they were probably not very 

 large or strong ; their digits were perhaps not more than four 

 in number. The length of our Loxomma cannot even approxi- 

 mately be estimated, in the absence of caudal vertebras. 



The ribs are long and strong and of reptilian type, showing 

 that the thorax was capacious, and that respiration must have 

 been vigorously carried on by means of diaphragm and lungs. 



As no scales or scutes have been found with the remains of 

 Loxomma, the skin may have been soft; perhaps further re- 

 searches may show that it had some defensive armour. 



On the whole we may conclude that Loxomma was a rather 

 sluggish reptile, capable, however, of vigorous movements, and 

 predacious, inhabiting the waters, swimming mostly like a fish, 

 but guided by its paddles, that it breathed air, however, like 

 the Alligators and Crocodiles of modern time. It must find its 



