A new bog chytrid
In our studies of the Phyeomycetes living in the diversity of habitats existing in the vicinity of the University of Michigan Biological Station, Douglas Lake, several chytrids have been encountered which seem characteristic of our boggy areas. One of these, Blyttiomyces helicus SPArrOW and B A ~ (1955) has already been described. Another, the subject of this paper, is a species of Phlyctochytrium which, like the Btyttiomyces, was isolated on pine pollen. This sparkling little chytrid was obtained from s0il collected in the middle of an almost dry bog now mostly given over to Vaccinium spp. Larix and Picea, but with residual areas of Sphagnum. In its distinctly stellate sporanginm and conspicuous spherical, endobiotic apophysis the new ohytrid was reminiscent of Phlyctochytrium reinboldtae PE~SlEL (1959). Strikingly unlike this species, however, each of the prominent rays or arms of the sporangial rudiment terminated in two pairs of delicate, brilliantly refractive spines which were set at right angles to one another. These delicate objects imparted an aspect to the whole structure which has been alluded to earlier as "sparkling". Because of the variation in number (4--8) and placement of the rays, irregularities in sporangial shape and size are produced (Fig. 2). Typically, the mature sporangia are sessile on the main body of the pollen grain and are 8--30 # broad by 6--25 # high (Figs.4--6). The endobiotic spherical apophysis is 7--18 # in diameter. Rarely, rhizoids can be found emerging from it after prolonged staining (Figs.4, 6). Occasionally, sporangia may have an external as well as internal apophysis (Fig. 1) or they may terminate a clavate, sometimes distally apophysate stalk (Figs. 3, 7). Zoospore production takes place as in other congeneric forms. The zoospores initiate motili ty within the sporangium and swarm violently out of pores produced at the tips of a varying number of rays upon the dissolution of the apex and teeth (Fig. 8). The zoospores are spherical, 4 # in diameter with a single bright refractive eccentric globule and a 15--20# long posterior flagellum. Movement is a gliding one punctuated by