Telegraph GK

[devadiva]

1d= The amount of three dimensional space occupied by an object. (6) V?????.
13a=Myhtological blood sucking witch who takes the form of a serpent (5) ??M?A.
16a= Somebody who cannot perceive colours seeing only shades of grey (11) ??N?C?R?MAT.
19a= Member of 19th century Irish Republican Brotherhood active in Irreland, US & UK (6) ?E?I?B.

[Aquagility]

Volume
Lamia
Monochromat
Fenian

[lloyd1e]

1d volume
13a lamia
16a monochromat
19a fenian

[devadiva]

Many thanks to both of you. Having every other letter, I thought that my word box would have come up with something. As for Lamia I've never heard of it. Thanks again for your help.