68 EXTINCT MONSTERS 
relatively larger, and we should imagine that they were very 
quick in detecting and catching their prey; their paddles also 
have larger bones. 
There is a remarkably fine specimen at Burlington House, in 
the rooms of the Geological Society, of an Ichthyosaurus’ head, 
which the writer found, on measuring, to be about five feet six 
inches long. A cast of this head is exhibited at the Natural 
History Museum. The largest of the specimens in the National 
Collection is twenty-two feet long and eight feet across the 
expanded paddles; but it is known that many attained much 
greater dimensions. Judging from detached heads and parts 
of skeletons, it is probable that some of them were between 
thirty and forty feet long. A specimen of Ichthyosaurus 
platyodon in the collection of the late Mr. Johnson, of 
Bristol, has an eye-cavity with a diameter of fourteen inches. 
This collection is now dispersed. 
With regard to their habits, Sir Richard Owen concludes that 
they occasionally sought the shores, crawled on the strand, and 
basked in the sunshine. His reason for this conjecture (which, 
however, is not confirmed by Dr. Fraas’s recent discoveries) is to 
be found in the bony structure connected with the fore paddles, 
which is not to be found in any porpoise, dolphin, grampus, or 
whale, and for want of which these creatures are so helpless when 
left high and dry on the shore. The structure in question is a 
strong bony arch, inverted and spanning across beneath the chest 
from one shoulder to the other. A fish-lizard, when so visiting 
the shore for sleep, or in the breeding season, would lie or crawl, 
1 Tt is, perhaps, hardly necessary to remark that whales are not fishes but 
mammals which have undergone great change in order to adapt themselves 
to a marine life. Their hind limbs have practically vanished, only a rudiment 
of them being left. But their external resemblance to the Ichthyosaur type is 
remarkable—dolphins especially so (see p. 73). 
