872 Marvels of the Universe 
nostrils, so far as the bony skull is concerned, opened into the very middle of the mouth. To get 
to the very bottom of the story, we have to turn to a very primitive Crocodile known as Belodon, 
from the Keuper of Wirtemberg, a creature nearly allied to a species which has been found in 
the Elgin Sandstone of Scotland. In Belodon, as is shown in the photograph on page 869, 
the external nostrils opened near the eyes, instead of at the top of the snout, while the internal, 
or posterior, nostrils opened directly under- 
neath. In this case it is a matter for debate 
whether victims could be dispatched after the 
method adopted by later Crocodiles ; per- 
chance, they were killed and eaten ashore. 
But how did the bony tube conveying 
the air to the back of the throat come into 
being ? It will be noticed that the inner, 
or posterior, nostrils of Belodon lie in a 
shallow trough, and it is easy to see how, by 
the gradual approach of the edges thereof, 
the trough became converted into a tube, 
which, gradually extending backwards, by 
the approximation of more and more of the 
edges of the trough, eventually extended to 
the very end of the skull, as in the Crocodiles 
and Alligators of to-day. 
All the ancient Crocodiles so far referred 
to were amphibious creatures, and lived in 
rivers, deep pools and estuaries, just as do 
their living relatives. But two extinct 
species are known which had forsaken these 
inland waters for the open sea. As a conse- 
quence, like the old Ichthyosaurs. and Plesio- 
saurs, or “ fish-lizards,’’ the Turtles, Whales 
and Porpoises lost the use of their limbs as 
supports on land by their conversion into 
paddles. One of these, the Geosaur, is shown 
in the accompanying restoration ; another, 
very like it, Weliorhynchus, has been found 
in the Oxford Clay of Peterborough. 
= 
Photo by) 
TT SPIDER-HUNTING WASPS 
THE SPIDER-HUNTER’S VICTIM. BY JOHN J. WARD, F.E.S. 
A paralysed spider has here been photographed hanging on the ; We 
fork of some grasses, where it has been deposited by the Spider- A PRETTY little Wasp, barely half an inch 
hunting Wasp out of the way of possible inarauders: The huntress in length, with shining black head and 
has gone off to find a suitable place in which to dig her burrow; she : 
will then carry off her prey. thorax, and an abdomen two-thirds red and 
the remaining part black, was resting on a thistle leaf while arranging her toilet. She had been so 
occupied for fully ten minutes, and was now smoothing out her fore-wings, which were smoky at 
their tips, excepting a conspicuous pale-coloured spot. So far as I know, this particular Wasp has 
no common name, although it, or some nearly-related insect, is, I think, known as the Path-Wasp. 
It, however, belongs to a family of the Solitary Wasps, and is recognized by the entomologist as 
the Spider- Hunter. 
