222 Ptib. Puget Sound Biol. Sta. Vol. 2, No. 41 



until the summer of 1917. At this time there were also found the Rhizo- 

 phidium and Stemphylium described below. 



Chytridium codicola, sp. nov. (PL 20, Figs. 5-7). Zoosporangia 

 erecta, sessilia, globosa vel ovoidea, 20 — 34 ^u, diametro metiens, hyalina ; 

 cytioplasma primo multis cum guttulis, deinde granulosum zoosporis nondum 

 perfectis ; operculum clausum invisible ; apertum rotundum, 6 — 8 ^x. diametro, 

 prope apicem sporangi ; mycelium saccatum, simplex, vesiculosum, guttula- 

 tum, hyalinum ; sporangia perdurantia endophytica non visa ; zoosporae 

 globosae, uniciliatae, hyalinae, uniguttulatae, 3 — 4 /x. 



Habitat in utriculis vivis Codii mucronati. Washington. Aestate. 



This sjiecies was collected on Codium mucronatum growing below 

 the littoral zone and attached to rocks on the southern shore of Turn 

 Island. This particular collecting ground is a transition between the 

 Ulva-association and the Laminariaceae-association with Alaria, Laminaria 

 and Ulva as the dominant genera and Codium mucronatum as a secondary 

 species. The individual plants of Chytridium codicola were attached to 

 the walls of the living utricles usually a short space from the mucrons. 

 The zoosporangium is erect, sessile, spherical to ovoid, 20 — 34 fi in diam- 

 eter, hyaline. At first the cytoplasm is many-guttulate but becomes 

 granular before spore-formation. The wall is smooth and of one thin 

 layer. The operculum when closed follows the contour of the zoospor- 

 angial wall so evenly that it cannot be detected until open. At maturity 

 of the zoospores the operculum opens and remains attached to the margin 

 of the aperture or disappears entirely. The circular aperture is about 

 6 — 8 fx in diameter and is located at or near the apex of the sporangium. 

 The penetration tube of the zoospore develops into a saccate mycelium 

 which is quite simple though often swollen or vesiculate, guttulate and 

 hyaline. No endophytic resting sporangia were observed. The zoospores 

 are globose, hyaline, uniguttulate, uniciliate and 3 — 4 /x in diameter. 



Rhizophidium codicola, sp. nov. (PI. 20, Figs. 1-4). Zoospor- 

 angia erecta, sessilia, globosa vel piriformia, 16 — 24 /x diametro metiens, 

 hyaliria; cytioplasma reticulatum, deinde granulosum, zoosporis nondum 

 perfectis ; mycelium est cellula irregularis, hyalina, multis cum filis ramosis, 

 minutissimis, vix cytioplasmate hospitis distinguendis ; zoosporae globosae, 

 hyalinae, uniciliatae, 2.5 — 3 /x, ex sporangi apertione irregulare egressae. 



Habitat in utriculis vivis Codii mucronati. Washington. Aestate. 



This minute organism was found with Chytridium codicola on the 

 utricles of Codium mucronatum collected on the southern shore of Turn 

 Island by Miss Annie May Hurd during the summer of 1917. It was 

 found in more abundance than the Chytridium. The zoosporangia are 

 erect, sessile, sperical to almost pyriform, 16 — 24/x in diameter, hyaline; 

 the cytoplasm is reticulate and then granular before zoospore formation. 

 The mycelium is an irregular, hyaline cell with many radiating, branched. 



