374 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY. 
muscles lie in such positions that their contraction depresses the folds on 
the metaepisterni into which ridges on the elytra catch when these are 
closed. This depression of the folds releases the elytra, or, if these are 
open, it allows them to be closed. 
2. Phagocytosis of the muscles of Coleoptera does not exist. No 
“Koérnchenkugeln ”” have been found, though leucocytes containing 
what are evidently foreign bodies have been found in Thymalus. These 
inclusions are possibly to be explained as intracellular parasites. 
