The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.
the general name for coelenterates of the orders Narcomedusae and Trachomedusae, belonging to the class Hydrozoa. Trachylida are characterized by the absence of a polyploid generation.
The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.