Looks like Pin and Cove which is helpful in dating. Personally, I think they are the prettiest of the dovetails
From:
http://www.scrgeek.com/woodwork/aboutDovetails.htmlOne of those styles that no longer sees a lot of favor is the pin and cove dovetail. It's the second one from the left up above. Around 1850, when America (and Europe) began to mechanize, master woodworkers were falling from grace rather quickly; there simply weren't enough of them to keep up with the demand for furniture. An American invention, and North American manufacturing's answer, was the pin and cove, a mechanized method which could be cut more quickly from a pattern by someone with a lower level of skill.
Not actually dovetails, pin and cove only lasted about 25 years or so... roughly 1870 to 1895. By then, "router" improvements and assembly line interchangeable drawer parts were cranking out picture perfect machined dovetails, and were firmly entrenched in the furniture industry. The whole Arts and Crafts movement was about the displaced master woodworkers taking back their craft from the machine. Still, pin and cove has a certain historical "charm" if you will, and it's a great way to date some late Victorian and Eastlake furniture.