model organisms

[French A. Lewis]

Does any one know of any invertebrate organisms that are less primitive
than C. elegans, and more primitive than Drosophila that are currently
being studied for neurobiology?

We are attempting to clone a C. elegans homologue of a human gene, and are
looking for an intermediate organism to jump to.   Any information would
be appreciated.

Thanks in advance,
French Lewis
CSI/IBR Center for Developmental Neuroscience