HYDRURUS. 1 87 



cess of division of the cells. Families irregularly spherical ; 

 cells arranged in radiating branched series, held by slender, 

 colorless, gelatinous threads ; cells with a , central many- 

 rayed chlorophyl body containing a large starch granule. 

 Diameter of cells, 10-13 p ; length, 18-20 jn. 



Frequent in Denmark, and Splitrock ponds, New Jersey, 

 September, 1885. 



A distinct form, but whether a plant strictly of this genus 

 or a mere condition of plant development may be ques- 

 tioned. The cells are larger than those of other species, the 

 form is different, the longer axis of the cells is parallel with 

 the radiating series, not the shorter one as in other species ; 

 the large central nucleus is another peculiarity, and the 

 cells are not so entirely confined to the periphery. 



Plate CLVII, fig. 12, a normal, well-developed specimen. 



Genus 52, HYDBUKUS, Ag. 



Thallus gelatinous, fixed at base, cylindrical or compressed, 

 elongated, 2-12 or more inches long; often variously divided, 

 sticky, surface naked or densely covered with delicate gelati- 

 nous, at times fasciculate, fibers. Cells in the beginning globose 

 or subglobose, afterwards elongated or elliptic, one or the other 

 pole colorless, arranged more or less regularly in longitudinal 

 families ; tegument thick, at length diffluent ; cells divide first 

 in one and then in two directions. 



HYDRURUS FOETIDUS, (Vill.) Kirch. 



Fronds gelatinous, attached at the base, about twelve 

 inches long, one inch wide in the middle, tapering both 

 ways ; very much and irregularly branched ; branches 

 scattered or crowded, simple or divided, gelatinous at first, 

 later more firm and elastic. Thallus solid, or rarely hollow, 

 seinipellucid, light green, olivaceous, or ochraceous, the 

 end simple or penicillate. Cells primarily globose or sub- 

 globose ; later somewhat conoid or elliptic. 



Diameters of cells range from 6-9 yw, with exceptions 

 larger and smaller. 



Syn. Conferva foetida, Villars, 1789. 

 Ulvafoetida, Vauch., 1802. 

 Rivularia foetida, DeCandolle, 1805. 

 Tremella myosuruSj Lyngb. , 1801. 

 Hy drums penicillatus, Ag. 

 Hydrurus Ducluzelii, Ag. 



