This is one cool spider. It is commonly called the oil-can spider. Take a close look at the body and you will see why they are called this. They are not common in Dominican amber (although I would not say they are rare). There is a little confusion in terminology of this genus: it is either Lasaeola or Dipoena (family Theridiidae). The amber is small and thin.
Homoptera, Fulgoroidea - there are 2 planthoppers in this piece of Dominican amber. One planthopper is very small. In fact the small one looks as though there is a mite on one of the back legs (but upon further inspection, it is not a mite)- really cool. Finally there is a large springtail, Collembola (not shown in pictures).
There are a lot of animals here, most are small but the important one is reasonable sized. That is a planthopper with all 4 wings spread. It is unusual to see all the wings like this, normally the best one can do are the 2 "front" wings. Also there is a midge, Diptera, Chironomidae, an unknown, a caddis fly, Trichoptera, a primitive fly, Nematocera,