SIKOSIPHON. 271 



the waves. Unlike the last S.pulvinatus, this is firmly 

 attached to the stones, or rocks. Have it also from other 

 parts of New Jersey, and from wet rocks, Mt. Mansfield, 

 Vt. The latter specimens have the filaments very irregu- 

 larly inflated, tuber-like. 



Plate CXCI, fig. 21, represents a single, rather large stem 

 from a tomentose mat on a stone, New Jersey. 



Plate CXCII, figs. 9-12, from specimens from Mt. Mans- 

 field, Yt. 



SlROSIPHON COMPACTUS, Kg. 



Forming a more or less expanded, compact, tomentose, 

 dark brown stratum, trichomes and branches ascending, a 

 little attenuated at the apices, obtuse, internally formed of a 

 single, rarely a double series of cells, which are torulose 

 and sometimes almost moniliform; diameter and length 

 nearly equal, filled with a pale blue-green, granular cytio- 

 plasm ; sheaths firm, golden brown ; heterocysts subglobose 

 or oblong. 



Diameter of filaments, 12-15 yw. 



Syn. Stigonema compactum, Kirch. ; Hassallia compada, Hass. ; 

 Scytonema compactum. Eng. Fla. 



Sandstone rocks, South Carolina; shaded limestone 

 rocks, Pennsylvania, etc. 



Plate CXCII, figs. 1, 2, several characteristic filaments. 



SlROSIPHON SCYTONEMATOIDES, ( Wood) Wolle. 



Filaments often closely intricate, flexuous or variously 

 curved, not rigid, (sparsely) branched ; cells uniseriate, 

 about equal in length to their diameter ; sheaths ample, not 

 distinctly lamellate, (their surface rough and corrugate) 

 transparent, (mostly) colorless, (sometimes light brown). 



Diameter of filaments, .00066" 16-17 //. 



This species was collected in South Carolina by Mr. Rav- 

 enel, growing on the limbs of Myrlca cerifera. There can 

 be little doubt that the form seen by Dr. Wood is the same 

 as already described (page 257) as Scytonema cortex, var. cor- 

 rugata. Doubting the validity of the normal condition of our 

 present plant, and not able to duplicate it for corroboration, 

 we retain the name selected by Dr. Wood for a plant, or a 

 condition of a plant, entirely distinct, but to which the 

 diagnosis applies well, omitting the few words we enclose in 



parentheses. 



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