Looks like a midshipman to me.
ok so I hit up san diego bay fishing from the rock with plastics like I do... great day got there at 5am 2nd cast caught a barracuda did not land but got him with in couple feet chaffed him off trying to grab him with the grippers he was close to 30 which would have been my personal best but things happen I will get another one... spotties are slow still got 11 of them no really big ones but ok size. oh I did catch some big mackerel. and a little old stingray that was oh about 40lbs and 4 foot around he hit a swimbait on the drop... and 5 halibut closest to a keeper was 19 inches... left at 12:30 to beat traffic home but im thrilled that was my first stinray and what a trip to fight so strong... oh and the unkown fish that i think is a lingcod
and it was probably a batray that you caught if it was 40#. STINGRAYS DON'T GET THAT BIG
I have caught rays like that one before, everyone I know calls them butterfly rays but I'm not sure if that's a nickname or if there is such a thing. its not a bat for sure, very flat compared to a bat ray.
I guess i can't be wrong all the time. here is a link for more info.
http://eol.org/pages/994815/overview