What Dev is the USB Port?


I have an iMac 233 original and I have Mac OS X running on it, I have 160Megs of memory and a 20Gig Hard drive and was wondering what /dev/ device file is one of my USB ports? Currently in my /dev directory I have:

bpf1 disk0s7 ptyp7 ptyq4 rdisk0s1 ttyp0 ttypd ttyqa
bpf2 fd ptyp8 ptyq5 rdisk0s2 ttyp1 ttype ttyqb
bpf3 klog ptyp9 ptyq6 rdisk0s3 ttyp2 ttypf ttyqc
console kmem ptypa ptyq7 rdisk0s4 ttyp3 ttyq0 ttyqd
cu.irda mem ptypb ptyq8 rdisk0s5 ttyp4 ttyq1 ttyqe
cu.modem null ptypc ptyq9 rdisk0s6 ttyp5 ttyq2 ttyqf
disk0 ptyp0 ptypd ptyqa rdisk0s7 ttyp6 ttyq3 zero
disk0s1 ptyp1 ptype ptyqb stderr ttyp7 ttyq4
disk0s2 ptyp2 ptypf ptyqc stdin ttyp8 ttyq5
disk0s3 ptyp3 ptyq0 ptyqd stdout ttyp9 ttyq6
disk0s4 ptyp4 ptyq1 ptyqe tty ttypa ttyq7
disk0s5 ptyp5 ptyq2 ptyqf tty.irda ttypb ttyq8

Any one know which one is a USB?
I've noticed that when I plug in my Imation LS-120, a new disk device entry appears in /dev. That makes me wonder if raw USB device numbers even show up in /dev, but I kind of doubt it unfortunately.
Maybe there's a USB daemon that can be told to create a /dev entry for a particular attached device. That would help.