Reviews — Dr. Linclstr din's Silurian Crustacea of Gotland. 33 



VI. — On some Rock Specimens from the Islands of the Fernando 



Noronha Group. 



By Professor A. Renakd, LL.D. 



THE rock specimens described in tins communication were col- 

 lected by J. G. Bucbanan, Esq., during the voyage of the 

 " Challenger." The islands have been described by Darwin in his 

 "Geological Observations on Volcanic Islands" (2nd edition, p. 27). 

 The author, after having explained the geological structure, gives 

 lithological descriptions of the chief types of the rocks, which may 

 be referred to the phonolites (St. Michael's Mount). These phono- 

 lites are composed of sanidine, augite, nepheline, hornblende, magne- 

 tite, nosean, and titanite. 



The rocks of Eat Island are basalts with nepheline. The con- 

 stituent minerals are augite and olivine. The ground-mass is almost 

 entirely composed of nepheline ; biotite and apatite occur as acces- 

 sory constituents. The little island known as Platform Island is 

 also basaltic, with a doleritic texture. It is composed of labradorite, 

 augite, olivine, magnetite, and biotite. The rock has undergone 

 alterations. 



VII. — Traces of Early Human Habitations on Deeside & Vicinity. 



By the Rev. J. G. Michie, A.M. 



CIRCULAR CAIRNS :— Their structure. Their probable uses- 

 human dwellings ; sepulchral purposes. Urns, chests (cists) 

 found in connection (Migvie). 



Yerd Houses : — General structure — examples in Cromer, Glen- 

 kindy, and Kildrummy. Probable uses. Generally found in the 

 vicinity of round cairns and circular foundations. 



Lake Dwellings (Crannogs):— Island in Lock Kinnord, Loch 

 of Leys. Similar to those found in Wigtonshire and Ayrshire. Dr. 

 Stuart's "Scottish Crannogs," and Dr. Munroe's "Ancient Scottish 

 Lake Dwellings." Relics found in connection — canoes, arrow-heads, 

 celts, stone knives, and stone cups. 



Moated Forts : — Lumphanan, Invernochty, Rothiemurchus, and 

 ruder form at Loch Davan. 



Ancient Pictish Towns : — Character and situation. Davan — 

 Short description of; probably the Devana of the Romans. 



E B V I E W S. 



I. — FoRTECKNING PA GoTLANDS SlLURISKA CrUSTACEER. Af G. 



Lindstrom. Tafl. xii.-xvi. (Ofversigt af Kong]. Vetenskaps- 

 Akademiens Forhandlingar, 1885, No. 6. Stockholm.) 

 A Catalogue of the Silurian Crustacea of Gotland. By G. 

 Lindstrom. 8vo. pp. 63, 5 Plates. 



TN the thirty years which have elapsed since the issue of Angelin's 

 great work " Palaeontologica Scandinavica," there, has been a 

 great accumulation of fresh fossil material from Swedish strata, 

 partly through the labours of Angelin himself, and partly through 



DECADE III. VOL. III. NO. I. 3 



