32 JOURNAL OF THE [January, 



Shark River had been transferred, and has since been culti- 

 vated with little difificulty. In November, 1887, I discovered a 

 third locality in Monmouth County, about five miles east of 

 that on the Shark River, near the seashore, at Ocean Beach, 

 New Jersey. 



At all these three points and in the tanks, more complex asso- 

 ciated forms have been since obtained and were at first attributed 

 to the Cladothrix dichotoma, Colin, and Crenothrix Kuhniana^ 

 Zopf, of Europe. 



The study of abundant material, from the natural localities 

 and laboratory-cultures, has shown that we have, at last at these 

 localities, and perhaps at other reported American occurrences 

 of supposed Crenothrix, a new genus of aquatic fungus of algoid 

 habit, which is a true schizomycete, branched, and apparently 

 the largest bacterium yet found, with filaments often 15 milli- 

 meters or more in length. 



In advance of the full description of this interesting plant, a 

 brief statement of its more important morphological character- 

 istics will be here presented. 



Though remarkably pleomorphic, all the stages of its growth 

 are sharply distinguished within two classes, the vegetative or 

 unicellular, and the reproductive or multicellular. 



From a microspore of ordinary form, leptothrix of various 

 kinds is produced by sprouting, viz., gently curved and twisted 

 filaments, irregularly bent spirochate and screw-filaments, 

 spirilla and vibrio-forms, all with distinct and thick sheaths, 

 often still more thickened by gelatinization and excretion of 

 ferric hydrate. Within the leptothrix-filaments, a condensation 

 of protoplasm ensues, producing, in some cases, cylinders and 

 granules, equal-sized cocci, and even arthrospores ; in others, 

 chains of connected bacilli, which may multiply by fission and 

 sometimes themselves develop minute endogenous spores. 

 These chains emerge from the original sheath and soon reveal 

 their investment by a still more delicate sheath, from which, in 

 turn, new chains of rectilinear elements emerge and generally 

 break up into their constituents. Both in the original lepto- 

 thrix and its secondary chains, many of the rods are often bent 

 or curved, sometimes vibrio-like, and by pressure, sometimes 

 penetrate the thinner sheath of the chains, and, so diverging from 

 the axis of the filament, form branches at a small angle. 



