58 SEA MOSSES. 



Cladopiiora arcta, Dillw. 

 The arched Chiiophora, of which wc give a fine 

 ami chanictcrisiic ilhistraiion in PLilc III., is named 

 from the i>cculiar habil of ils growth. The branches 

 divide and suMivitle by cMremely acute angles, and 

 the ramifications arc all very straight, 'ITiis prevents 

 the unsymmcirical outline common to most plants of 

 this genus, kcci)s the brunches somewliat close together 

 as they rise upward, and, at the same time, permits 

 them to seixiralc gradually and s)-mmetrically. Ihis 

 gives the tuft its arched and graceful form, not unlike 

 the outline of our more perfect and Ixrautiful elms. 

 This characteristic of form, the yellowish green color, 

 and the deciiledly glossy or silky look, which the 

 phnt usually presents when dr)' and pressed on i»ai>er, 

 makers its dctennination easy. Another \ ity 



which may U- nolicetl in the dried sjiccimen is the 

 disposition of the chlorophyl of the tcnuinal brai. 

 to collect in the extreme end cell, making that cell 

 have a disiint tly darker green color than the ceUs just 

 below it in the branch. It is an annual. Mr. Collins 

 finds it common at Nahant and Nanlaskel, on rocks 

 Ixrtween tides, from March to July. Miss Booth finds it 

 extremely rare at Peconic Ikiy. L. I. .M M.irblehearl I 

 gathered it fre<iuenily during the summer months. It is 

 often found on the California coast, near Smta Crux. 



