212 ZOOLOGICAL GLEANINGS 



shark also, it had its gill-clefts placed on either side 

 of its head, and not on the under surface of its body 

 as they are in all skates and rays : unlike those of 

 most sharks, however, were its pectoral fins ; for these, 

 instead of standing out at right angles to the body, 

 were produced to form a pair of flaps running forward 

 with a slight twist, one on either side of the head. 

 If we could have seen the embryo at a later stage, 

 we should have found that these two flaps had fused 

 with the head, so as to push the gill-clefts down to the 

 under surface and to produce the broad, disk-like body 

 characteristic of the skates and rays. There are some 

 rays, such as the sea-devils {Dicerobatis and Ceratoplera), 

 in which the flap-like anterior prolongations of the 

 pectoral fins are not entirely fused with the head, but 

 stand out in front of it like a pair of horns : these, 

 judging from the form of the embryo of Pteroplatcea 

 micrura, may perhaps be regarded as ''unfinished" rays. 

 Again, there is a peculiar shark — the monk-fish or angel- 

 fish {Rhina sqttatind) — in which the front part of the 

 pectoral fins have, as in the early embryo of Pteroplatcea 

 micrura, the form of a pair of flaps enveloping the sides 

 of the head, but not fused with it : this singular shark 

 may perhaps be regarded as venerable first cousin of 

 the ancestor of all the skates and rays. 



The sandy stretches along the Godavari and Kistna 

 coasts are copiously honeycombed with the burrows of 

 the red ocypode crab {Ocypoda macrocera) as are the mud 



