188 Proceedings of the Royal Physical Society. 



Fig. 26. Archides'inus Macnicoli. — Natural size. From specimen belonging 

 to James Powrie, Esq. 



Fig. 2c. Diagram of larger and smaller segments of Archidesmus Macnicoli, 

 to compare with fig. 3a. 



Fig. 2d. Leg of fig. 2 magnified to show spines at the articulations. 



Fig. 3. Craspedesoma Raulinsii. — Recent, from Queen's Park, Edinburgh, 

 for comparison. 



Fig. 3a. Diagrammatic double segment of Craspedesoma to compare with 

 figs. \g and 2c. 



Fig. 4. lulus Blainvillii to compare with fig. Ic, Copied from figure in 

 Gervais' ** Insectes Apthres, " 



X. Additional Notes on the Algce of the Firth of Forth. 

 By George William Traill, Esq. (Communicated by 

 Professor Duns.) 



(Read 18th January 1882.) 



List of fourteen species new to the Tirth of Forth, dis- 

 covered by G. W. Traill during the year 1881, including 

 several which are new to Britain; with exhibition of 

 specimens. 



1. Cladophora centralis, Lyng. — A new Cladophora found 



sparingly at Joppa, in muddy pools, near high 

 water, identified by Mrs Merrifield as the Clado- 

 jphora centralis of Lyngbye, and new to Britain. 



2. Bhizoclonium riparium. — Caroline Park and Joppa 



rocks, parasitical on algse. 



3. Urospora pencilliformis, Areschoug. — Not uncommon 



at many places in the Firth of Forth, such as 

 Earlsferry, Kinghorn, Burntisland, Inchcolm, 

 Gran ton, very fine ; Joppa, Fisherrow Pier, 

 North Berwick, Broxmouth, always associated 

 with Vlothrix flacca ; on rocks, and sometimes 

 on fuci, near high water ; perennial, fruiting in 

 winter. Found also by Mr Holmes at Ventnor 

 in Marcli 1880, and then new to Britain. 



4. Cladostephus distichus, Holmes. — The plants found by 



me at Kincraig in 1879, and considered to be a 

 broad variety of Chmtopteris phcmosa, with some- 

 what different branching, Mr Holmes now forms 



