ADG1234 analog inputs clamping diodes

Hi,
We plan to use the ADG1234 in one of our products. It will be powered with +/-15V rails (see picture attached). We would like to protect it against over voltages up to +/-25V. There is a 220R series resistor with each analog input we want to protect. We can't increase the resistor value to keep enough BW.

So my questions are :

1. Are there clamping diode to VSS in the ADG1234?
2. In order to handle the max current in over voltage condition (around 50mA), could you please suggest protection diodes (connected between input/output terminals and VDD, VSS) with very low capacitance (let's say 1pF total max.) which can meet the ADG1234 specs & our 25V input protection requirement?
   
   

Thank you in advance,