A NEW SPECIES OF ACHLYA 



By W. C. CoKEK and J. N. Couch 



Achlya Orion n. sp. 



Hy])lial threads long, reaching a length of 1.5 ems. on honse-flies, 

 more slender than in most Achlyas, from 10-40/x thick close to base, 

 rarely up to 85/i, thick, often wavy; usually little branched and 

 pointed at tips when young ; becoming considerably branched with 

 age. Sporangia abundant, cylindrical, usually" borne singly on the 

 tips of the main hyphae in young cultures, renewed by cymose branch- 

 ing, often forming several clusters at regular intervals on the same 

 hypha, irregular and wavy in old cultures, 12-37 x 36-600/x (rarely 

 up to 900/i,). Spores 9-10/x thick, emerging as usual in Achlya, but 

 often falling to the bottom in an open group instead of forming a 

 sphere at the sporangium mouth. Oogonia abundant on flies, grubs 

 and vegetable media, spread over the entire culture from bases of 

 h3^phae to tips, giving the culture a lacy interwoven or net-work ap- 

 pearance ; the diameter 30-60/x,, commonly 32-48|U. ; usually borne singly 

 on long, crooked, recurved stalks which arise racemosely from main 

 hyphae and which vary in length from 2-10 times the diameter of 

 •the oogonia; often oogonial stalks ma.v branch bearing two 

 oogonia and rarel.y oogonia may be borne on a stalk which arises 

 directly from another oogonial wall ; very rarely intercalary ; oogonial 

 wall usually without pits (except where the antheridial tubes enter) 

 when grown on flies or grubs, but as a rule with pits when grown on 

 boiled corn. Eggs 1-8, usually 1 or 2 in each oogonium; 25-45/i, in 

 diameter, most 33-36/a, eccentric when ripe with one large oil drop ; 

 usually spherical, but often elliptical from pressure. Antheridial 

 branches almost always androgynous, usually arising from the oogon- 

 ial stalk itself, less often from the main hyphae ; rarely diclinous ; an- 

 theridia on about 75% of the oogonia, one or two on an oogonium, 

 tuberous; antheridial tubes obvious penetrating the oogonia and 

 reaching the eggs. 



The species seems to be quite rare, having been recognized only 

 twice in considerably over a thousand collections, made by the senior 

 author and his students. It was found in some water and trash 

 collected from the west branch above the Meeting of the Waters 



