08C1 LLAT0B1 \< B r. 



compared with an authentic specimen of Chauvin's 

 plant, received firom M. Lenormand, and find them to 

 utial particulars. The chief difference is 

 in colour, the [rish Bpecimen having lost its original pur- 

 ple, and acquired a greenish shade, no uncommon effecl 

 of decay. 



Oedeb 17. OSCILLATORIAi 



\» l\. 1M\ U.AKIA. 



350. plicata [The folded Ii } ir/>/<rr<>r) \ fronds rather large, 

 densely gregarious, gelatinous, compresso-plicate, often hol- 

 low and at Length ruptured, dark-green; filaments ,i 

 associated in dichotomous series, tapering to a fine | 

 CarnUch., Earv. in Hook. Br. Fl. v. 2. p. 392. A.tlab, 

 PL LXXV. Pig. 351.) 

 Lichen corrugatus, Dickson! (fide BorrerJ. 

 llnh. On the rocky sea-shore, about high-water mark. 

 situations only occasionally overflowed by -alt-water. 

 A well-marked Bpecies oi Rivularia, easily recognized, 

 and not uncommon on Beveral parts of our shores. It was 



noticed by the late Captain Carmichael on th 

 coast of Scotland. Like R. nitida, it becomes hollow in 

 age, bul may always be known from thai Bpecies by its 

 much darker and duller colour, smaller size, and the dif- 

 ference of habitat. The fronds are very irregular in Bhape, 

 and alter considerably as they advance {<> maturity, by the 

 lateral pressure of one frond on another. I cannot say 

 anything in praise of the beauty of this production; what 

 it has, it keeps concealed, or reserves lor microscopic 

 351. atra {Tin- black Rivularia) \ fronds minute, scattered, glo- 

 bose or hemispherical, linn, smooth, glossy black-green; 

 filaments dark-green, densely packed, Both, Cat. But. 

 p. 340. A PLAS, PL I AW'. Fig. 352. 

 Euactis atra, Ktz. Linckia atra, Lyngb. L. hemisphserica, & 

 Tremella hemisphssrica, / Chstophora atra, Ag. 



Ih'h. On rocks and Btones, and on CJoralunea and other Algse, 

 between tide-marks. Perennial? At all seas 

 A very common plant on all rocky shores, growing either 

 ks or«.n the smaller Algae, especially on Clado- 

 \alis. It forms small, 

 bard, wart-like halls or hemispheres, rarely as 

 i eel -]>ea. and sometimes compL 



the plants to which it attaches itself. 



