24 COLLINS AND HERVEY. 



*2. S. CALCICOLA Rabenhorst ex Gomont, 1893, p. 45, PI. VIII, 

 figs. 1-3; P. B.-A., No. 2158. On shaded wall of house near South 

 Road, Dec., Collins. 



FAMILY NOSTOCHACEAE. 

 ANABAENA Bory. 



1. Spores ovoid, not contiguous to heterocysts. 1. A. variabilis. 



1. Spores subcylindrical, contiguous to heterocysts. 2. A. torulosa. 



*1. A. VARIABILIS Kiitzing ex Bornet & Flahault, 1888, p. 226, 

 P. B.-A., No. 2059. Sphaerozyga Thwaitcsii Harvey, 1846-51, PL 

 CXIII. B. Brackish pool, April, Collins; in reservoir near Spanish 

 Rock, Jan., Hervey. In the material from the latter station the 

 filaments were sometimes straight, but oftener curved as in A. flos- 

 aquac Breb. ; the spores were those of A. variabilis. 



2. A. TORULOSA Lagerheim ex Bornet & Flahault, 1888, p. 236. 

 Among other algae, North Shore, Aug., Collins. 



Sterile filaments of an Anabaena or Cylindrospermwn were found on 

 ground wet by rain, near Flatts Bridge, Aug., Collins. The cells 

 were about 4 /* diam., spherical, or just after division discoid. 



HORMOTHAMNION Grunow. 



H. convolutum sp. nov. Trichomatibus pallide aerugineis, in- 

 terdum rubescentibus, parallelis, elongatis, 3-5 /JL diam. ; cellulis 1-4 

 diam. longis, cylindricis, nodis leviter constrictis; heterocystis ovoi- 

 deis vel sphaericis, 8-10 /JL diam. ; sporis ? ; fasciculis tenuibus, inter 

 utriculis hospitis penetrantibus, curvatis. 



Trichomes pale aerugineous, sometimes with a shade of red, parallel, 

 long, 3-5 AI diam.; cells 1-4 diam. long, cylindrical, slightly constricted 

 at the nodes; heterocysts ovoid to spherical, 8-10 y, diam.; spores ?; 

 fascicles slender, winding among the utricles of the host. On C odium 

 tomentosum, Cooper's Island, Aug. 29, 1913, F. S. Collins. Type in 

 Collins herb., No. 7239. 



More slender than the other species of the genus, the cells relatively 

 longer. The cluster of filaments winds about among the utricles of 

 the host, the continued growth of the two plants causing the endophyte 

 to turn and twist very sharply. 



