We've been seeing the Red-veined Meadowhawk recently at Smiley's Bottom here in Anacortes. In fact, Smiley's Bottom is the only place we've ever seen the Red-veined Meadowhawk. It's an interesting species, but not widespread.
The Red-veined Meadowhawk can be mistaken for the Cardinal Meadowhawk. After all, it has white spots on the sides of the thorax like the Cardinal Meadowhawk, as well as some red in the wings. Here's a look at a male Red-veined Meadowhawk:
You can just see a white spot on the thorax under the wings—there are two white spots on either side of the thorax, but it's hard to get a good look at them through the wings. In addition, notice the black markings along the sides of the abdomen. These features are pointed out below:
For comparison, let's take a look at the Cardinal Meadowhawk. Here's a male, showing the pure red abdomen and a white spot on the thorax:
Perhaps the best distinguishing feature is the dark red parch on the wings near the base in the Cardinal Meadowhaw. This is shown below:
This dark red, opaque patch is unique to the Cardinal Meadowhawk.
It's not surprising that humans sometimes mix up these two species—they seem to do that themselves. In the following photo we see a male Red-veined Meadowhawk in tandem with a female Cardinal Meadowhawk:
The following photo shows the more typical situation—a male Red-veined Meadowhawk attached to a female of the same species:
This species lays eggs as the pair hovers in tandem, with the female flicking out one or two eggs at a time. The eggs, which look like small grains of rice, tumble down into the vegetation and onto the ground. It's interesting to note that the ground is dry when the eggs are deposited, but is underwater when the Fall rains return.
You can find out more about this species and others in Common Dragonflies and Damselflies of the Pacific Coast.