Re: What kind of spider is velvet, black with an orange line down the back?

I suspect that you may have a form of the black widow, possibly 
Latrodectus variolus (the Northern Black Widow), which usually has a row 
of red or orange dots down its back (dorsal abdomen), which might be fused 
in some specimens.   Another possibility would be Latrodectus hesperus 
(the Western Black Widow).   Since I do not know what the underside looks 
like (it should have a red hourglass or possibly two red triangles as 
common in L. variolus) I cannot identify this spider for certain.   The 
picture you saw on the Dutch book appears to be Latrodectus hasselti (the 
Australian Red Back Spider), which, as far as I know, has not been 
imported to the United States (although it was fairly recently 
accidentally imported into Japan.)

References:

Kaston, B. J.  1978. How to Know the Spiders, 3rd ed. McGraw-Hill, Boston.

Main, B. Y.  1976. Spiders. Collins, Sydney.

Latrodectus on Arachnology at  http://www.ufsia.ac.be/Arachnology/Pages/Latrodectus.html