FKKSH-W A 1 Hi: ALli.K UK T 11 K I .\ 1 I I' I) STATES. 83 



division, they arc elliptical. Thry arc of n bright green color and almost always 

 have a conspii -nous rounded granule within tlirni ; sometimes, but not commonly, at 

 one end then- is a hj aline space or vesicle, similar to that seen in zoospores. I 

 lia\c watched tlic prodm tion of /oosp.,res in a plant gathered late in November. 

 The cinter wall of the cell is always so thin as to be scarcely perceptible, and when 

 the /oosporc is beginning to move, it looks as though the \\hole cell were rocking, 

 the thin outer coating beini; lost to eight. After a considerable period of vain 

 rrl'ort the /oospore c-i ap< - from the thick gelatinous mass which surrounds it. It 

 is hiciliated, roundish, and furnished with a hyaline space at the end. 



I have observed a '!'< /r<i"j>ora growing in rapidly running water, which some 

 would no doubt consider distinct, but which seems to me rather a variety. The 

 itc frond was of a very vivid green, erect, buoyed up by an air-bubble con- 

 tained in its upper end. Its shape was that of a long sack widened very much 

 above, and below constricted into a fine point, by which it was firmly attached. 

 In some instances it attained a length of seven or eight inches. In all other 

 rcsprrts these plants agreed with the others found in quiet water. 



The species of this genus are to me not at all well-defined in any work which I 

 ha\c had access to. The plant now under consideration abounds everywhere in 

 tins neighborhood, and is without doubt the one identified by Prof. Bailey as T. 

 ijtliitintuta (Vauch), of which, however, he afterwards states that Prof. Harvey, to 

 whom he had sent specimens, writes that it is a distinct species, and proposes to 

 call it jxrforala. In my Prodromus I referred the plant to T. lubrica (Roth). 

 My reasons for doing this were that the size of the cells corresponds very closely 

 with the measurements of that species as given by Prof. Rabenhorst, and the 

 absence of anything that seemed to me definite in the descriptions of the two 

 :es. Moreover, if the possession of a parietal hyaline spot be not simply an 

 accident of growth, it would indicate that the plant belongs to P. lubrica. I do 

 not think, however, that any importance is to be attached to this, as the vacuole 

 is often absent, and, although Prof. Rabenhorst makes no mention of it, is, in all 

 ability, present in certain states or stages of T. gclatinosa. My own convic- 

 tion is, at present, that T. gdatinosa and T. htbrica are very probably synonyms. 

 If they be distinct, the plant from which the above description was taken is refer- 

 riblc to T. perforata (Harvey), which, if not new, is a form of T. lubrica rather 

 than T. gelatinosa. If T. lubrica and T. gelatinosa be united, no grounds are left 

 for sustaining the separateness of T. perforata. 



Whilst botanizing in a primeval glade and forest, known as Bear Meadows, in 

 this State, I came across a spring, covered with a Tetraspora, which appears to 

 represent the T. gelatinoea type. It formed great masses half an inch in thickness, 

 at first attached, afterwards floating and covering the surface of the pool for several 

 feet each way. When young these masses were elongated and were formed of 

 numerous lobes attached often by very slender pedicles, and having their margins 

 thickened and undulated so as to give a beautiful waved appearance to the light 

 green mass. Under the microscope the structure was similar to that of the other 

 form, except that the cells varied more and attained a greater size. Their diame- 

 ters ranged from JT >yj* = 0.00027" to T3 J 5 / = 000066*. 



