From: "Erin Barley" < >
Subject: mystery midge
Date: Tue, 21 Oct 2003 16:30:50 -0700

Hi Ian,Could you post this mystery midge?

I found a number of these in a long core from the Yukon. I managed a
couple of photos, though the specimens were poorly preserved. My
labmate recently found lots of well preserved specimens from this
same group in a Venezuelan surface sample. In both cases diversity
was low, and Limnophyes was also found in significant numbers.

Description: A single median tooth, with median nipple. In good
specimens, the 'nipple' is sharp and possibly thicker than the
surrounding shoulders of the median. 5 laterals, with the 4th and 5th
laterals a little closer together than the other laterals. The median and
laterals are on different layers, and where they overlap a darker stripe
appears (most visible in pale specimens) - possibly a ventromental
plate? There are 2 ventromental plate-like lines: one the extension
from the median tooth, the other longer one continues down from the
outer edge of the mentum. I think the mandible has 4 inner teeth.

Any suggestions appreciated!
Erin

Erin
Erin Barley
MSc student
Dept of Biological Sciences
Simon Fraser University

Mailing address:
Department of Biology
Okanagan University College
3333 College Way
Kelowna, BC, V1V 1V7