104) BRITISH SEA-WEEDS. \_Mela7iosj)ermecB. 



Curdie, M.D., on the shore of the island of Gigha, off 

 Kintyre. It takes its specific name from its resemblance 

 to heath. It has in a very remarkable degree the property 

 of being iridescent when under water in a growing state. 

 In drying it becomes nearly black, and does not adhere to 

 paper. 



I shall n^erely name the other British species of which 

 I have specimens, but have never seen in a growing state. 

 So far as I known, not one has been found in Scotland. 



2. C^stoseira granulata, Ag. 4. C^/st.fceniculacea, Grev. 

 •X- 3^ harhata, Ag. 5. fibrosa, Ag. 



Genus III. HALIDRYS, Li/ngb. 



Generic Character. Frond compressed, coriaceous, linear, pin- 

 nated with disticboiis branches. Air-vessels lanceolate, stalked, 

 divided by transverse septa. Receptacles lanceolate, stalked, 

 compressed. Seeds in distinct cells. — The name is from two 

 Greek words signifying sea and oak. — Greville. 



1. IIalidrys siliquosa, Lynrjhyc. (Plate I. fig. 2. Portion 

 of frond.) 



The frond is narrow, compressed, branches distichous, 

 alternate, vesicles stalked, oblong; receptacles stalked 



