650 AQUATIC PHYCOMYCETES 



? Coelomomyces sp. Couch and Dodge 

 J. Elisha Mitchell Sci. Soc.., 63: 75. 1947 



Resting spores oval, flattened on one side, with the usual longitudinal 

 groove, 31-38 by 42-60 [jl, with a pale brown, smooth to minutely pitted 

 wall, the pits scattered or arranged in transverse lines, thus giving a 

 striated appearance. 



In larvae of Anopheles crucians, United States. 



Intermingled with typical Coelomomyces dodgei. 



CATENARIACEAE » 



Thallus intra- and extramatrical, cylindrical, branched or unbranched, 

 septate, the septa delimiting the rudiments of reproductive organs or 

 sterile isthmuses, bearing numerous rhizoids; zoosporangia formed as 

 enlargements of the axes of the thallus, frequently in linear series con- 

 nected by narrow septate isthmuses, variable in shape; zoospore for- 

 mation, structure, and discharge as for order; resting spores formed 

 singly and loosely within a zoosporangium-like structure or in segments 

 of the hypha, their wall somewhat thickened, smooth or very minutely 

 pitted, pale brown, upon germination developing a discharge tube and 

 functioning as a sporangium, the uniflagellate swarmers giving rise 

 either directly to new asexual plants or encysting, each of the cysts 

 serving as a gametangium and forming endogenously four uniflagellate 

 isogamous gametes which fuse in pairs to produce a biflagellate zygote, 

 the zygote upon germination establishing a nonsexual thallus. 



Parasites of microscopic worms and of fungi; also, saprophytes on 

 a variety of plant and animal substrata. 



As a result of careful observation of Catenaria, Couch (1945a) raised 

 the subfamily Catenarioideae (Sparrow, 1943) to a family and moved 

 it from the Chytridiales to the Blastocladiales. He cited as reasons the 

 resemblance in structure, manner of discharge, movement, and germi- 

 nation of the zoospores, and the similarity in place of formation of the 

 resting spore, the kind of septation, and the type of life history. 



On much the same grounds, Catenomyces Hanson is included in this 

 family of the Blastocladiales rather than placed in one of the Chytri- 

 diales. 



1 Couch, Mycologia, 37: 187. 1945. 



