PISCES 155 



body abruptly. The immensely developed pectoral fins contri- 

 bute in great degree to the breadth, and the girdle joining the 

 fins may be distinctly seen and felt in the mid- ventral region of 



FIG. 75. Raia clavata. A series of embryos to illustrate the change from the 

 early round condition to the flattened state. The figures show also the 

 change in position of the dorsal fins produced by growth, the disappearance 

 of the ventral median fin, the expansion of the paired and especially 

 of the pectoral fins. The external branchial filaments are also indicated. 

 From a series kindly lent by Mr. R. S. Clark. 



the body. The pelvic fins are much smaller, and are placed on 

 each side posteriorly between the pectoral fins and the tail. 

 There are two small dorsal fins near the extremity of the tail, 

 but it will be seen from fig. 75 that in the embryo they are 



