184 A Q UA TIC PH YCOM YCETES 



geton and also the use of the name in denoting a family. He suggests 

 Septolpidiaceae in its place. Since he had no new evidence on Ach- 

 lyogeton, he concluded, however, that Achlyogetonaceae should be 

 retained. 



ACHLYOGETON ENTOPHYTUM Scheilk 



Bot. Zeitung, 17: 398, pi. 13, fig. A, 1-8. 1859 

 (Fig. 15 A-B, p. 186) 



Sporangia from two to fifteen, strongly constricted at the stout cross 

 walls, individuals ellipsoidal or subellipsoidal, 15-55 \x by 9.6-20.4 u,, 

 wall smooth, slightly thickened, discharge tube arising at right angles 

 to the long axis of the sporangium, fairly broad, generally expanded 

 where it makes contact with the inner wall of the alga and prolonged 

 outside for a varying distance (up to 60 u,); zoospores ovoid or broadly 

 pyriform, with a colorless refractive basal globule, a vacuole, and a 

 flagellum about three times as long as the body, emerging as elongate 

 bodies upon the rupturing of the slightly expanded tip of the discharge 

 tube and forming at the orifice a group of spherical cysts 4 \x in diameter, 

 issuing from these after a period of rest and swimming away; resting 

 spore possibly not as yet observed. 



In Cladophora sp., Schenk (loc. cit.), Germany; "Confervacees," 

 Sorokin (1883:38, fig. 48), Asiatic Russia; Cladophora sp., Martin 

 (1927: 188, fig. 1), United States; Cladophora sp., Tokunaga (1934a: 

 227, fig. I), Japan. 



Sorokin (1876:63, pi. 3, figs. 2-5) reported the species as occur- 

 ring in Anguillula in European Russia. A further morphological study 

 of this form is necessary before it can be considered identical with 

 the alga inhabitant. It is certain from Sorokin's account that the 

 typical encystment of the spores occurred after discharge. From his 

 Plate 3, figure 5, it is also evident that the sporangia which had thin 

 cross walls were not simultaneously formed from the tubular thallus, 

 but progressively, as in Septolpidium. 



Both Martin and Tokunaga noted resting bodies associated with 

 sporangia. As Tokunaga suggested, the round thick-walled resting 

 cells observed by him, each of which was accompanied by a com- 



