It looks like you have created an Extended partition with Partition Magic, and then created a single Logical partition taking up all the available space in the Extended partition.
I seem to recall that you can have a maximum of 4 partitions on a disk, due to the way that the MBR is structured. Of these, at least 3 must be Primary partitions, with the 4th being either a Primary or Extended partition. The extended partition may then have multiple Logical partitions created within it. The upper limit escapes me at the moment, but the practical limits are disk size and drive letter!
You can just leave things as they are, or if you wish, use PM to remove the logical and extended partitions and simply create a Primary partition instead. Yes, it is data destructive!
SD