( i;i; mm n . 133 



times as Long as broad, of the ramuli Bhorl ; dissepiments 

 Hen, opaque ; apices hooked Inwards ; tetraspores whorled 



in the joint-, depressed ; favellse in the ultimate forking 



the branches, or on Lateral ramuli, Lnvolucrate, Roth : I 



Bot r. 3. p. L54. Ltlas, PL LIL Pig. 237.) 

 Hormooeras diaphanum, Ktz. Conferva diaphana, Lightf, ('. 



nodulosa, Huds. Boryna diaphana, Qrat. 

 Huh. Parasitical on several of the smaller AJgee, in r>>rn- ] 



between tide-marks; sometimes growing on rocks. Annual. 



Summer. 

 This is the typical form of the old Conferva diaphana 

 of British authors, the Longest known of the extensive 

 group ^\' the genus to which it belongs: a group which 

 contains numerous very distinct plants, which wore once 

 confounded together as varieties of the species uow under 

 review. From the British species of this section, except 

 one, our C. diaphanum may be at once known by its Larger 

 size and more robust filaments ; it is also well characterized 

 by the lateral dichotomous ramuli given off all along the 

 principal divisions <A* the frond, and by the gradualli 

 nuated filaments. These last characters distinguish it from 

 C nodosum and C.fastigiatum. 



231. gracillimnm {The very slender Cerammm)\ frond i 



Bively Blender, of nearly equal diameter throughout, very 

 flaccid and gelatinous, dichotomous j the branches sel with 



1111111110, flabellifbrm, dichotomous ramuli; articulations 



lourless, those of the branches live or six times as I0112: as 

 broad, 1 1 1< >-i* of the ramuli very short ; dissepiments opaque, 



purple; favella 1 home on the lateral ramuli, with a spread- 

 ing, many-rayed involucre, Ha/rv. Phyc. Brit. j>l. 201;. 

 232.) 

 Hormooeras gracillimum, Kiltz. 



JIah. On mussel-shells, and on Corallina officinalis and other 

 small Algae, exp Ltreme low-water. Annual. Sep- 



tember. 

 This species has a softer and more gelatinous substance 

 than any British Ceramium, and this character, with its 

 extreme tenuity, and the minute, fastigiate lateral branch- 

 eadily distinguish it from any of the section of the 

 - to which it belongs. 0. gracillimum is the smallest 

 and most Blender of our British Ceramia. So slender are 

 its threads, so flaccid, and so densely* crowded together, 

 that it is almost impossible to display them properly 00 

 paper. They almost invariably become enta 



