Don't get too excited. It is not unusual for young lemon trees to bear fruit with very thick rinds. Be sure the fruit is ripe before picking as it is a slow process with lemons. When ripe it is very easy to tell the difference between a Meyers and a Eureka, or a Ponderosa. Al

I had to pick it early because there was a caterpiller attacking the first lemon, but next time I will keep them on longer and see. Thanks, that is a relief. I don't have room for more then one lemon tree.

tropical thought,
Doesn't look like a Ponderosa to me, the lemons would be much, much larger. I agree with calistoga, you need to wait and let the fruit ripen before picking. It can take a year for those first lemons to ripen up, and if they're Meyer Improved lemons, the skin will get thinner and thinner, and they will be a deep, rich yellow color. You'll know they're ripe because the the lemons will have some give to them (softer) when you gently squeeze them. The lemons will also be yellower and rounder than other lemons (Eureka or Lisbon). As you probably know, lemons, including Meyers, will have fruit at varying degrees of ripeness on them at any given time, along with flowers. Meyers also tend to have cyclical crops (a few months of heavier "crop-type" production) due to it's heritage, more so than other lemons that are true lemons (Meyer is not a true lemon, but a cross between either a sweet orange or mandarin and a lemon). My Meyer is this way, I have a much heavier crop from about now through about June or July, although some folks see the cyclical crop more around November through March. The ripe lemons store very well on the tree, so I pick as I need, but by May, I've pretty much stripped the tree of ripe fruit, and will only get a handful until next January. So, "patience, grasshopper!" And, if you've got a caterpillar "attacking" the fruit, treat the tree for caterpillars, don't pick premature fruit. It won't taste good, and you'll lose your crop! I've included the link about Meyer Improved from the UC Riverside Citrus Collection, but here's another good article about the Meyer Lemon that might be helpful:
http://www.suite101.com/content/growing-an-improved-meyer-lemon-tree-in-the-home-garden-a250490

Patty S.

Here is a link that might be useful: UC Riverside Citrus Collection - Meyer Improved Lemon

May I suggest that you 'document' your concerns with the place you bought the tree you suspect may have been mislabled? At the very least, if you find that you don't have a Meyer, they will owe you a replacement tree ... possibly a larger, more mature one.... you will have 'lost' a year. Sometimes recording your concerns will help the grower or nursery do the right thing.

BTW ... I crushed a leaf on my Meyer to see if there was a distinctive scent ... seemed like it was, but didn't have a regular lemon to compare with.

Good luck, and keep us posted on the outcome .... Makes me think of a bare root BEVERLY HILLS apple that after many years waiting for apples, produced a very inferior peach. I considered it a joke on me, as the foliar differences between apple and peach are very distinctive.

The nursery said I should take them a leaf, and they swear it is a Meyer lemon tree. The only yellow lemon is small, I had to spray it a bit you know, but I hope I won't die of cancer, because since you take off the peel and I did not use the systematic one. The caterpillars were destroying each leaf and each fruit. It was spray or chuck the whole concept of growing lemons. It looks more like a eureka, but not like the ponderosa leaf. These lemons look like tiny eurekas, but eureka is just as good as a Meyer to me. So, at least it is not a ponderosa. Those leaves are oblong.

The only pests I ever see on a citrus are slugs/snails,ants or aphids/scale, have never seen a caterpillar on a citrus. The only spraying I ever do is Ultra-Fine horticultural oil which if done weekly for three weeks will usually eliminate the aphids/scale and with the honeydew that feeds the ants gone they will lose interest. Baiting the garden for snails and slugs will solve that problem. There is no reason to use anything toxic on your lemon tree. Al