1815.] JFeriierian Natural Histnry Society. 13/ 



* Pinna anali. 



1 . Pinna oautlalis lunata . . ^ .StjUalus. 



2. Pinna aiudalis irregularis Galeus. 



* Pinna anali nulla, 



3. Os arvte oculos situm Squatlna. 



4. Os pone oculos situm Acanthias. 



The two species which he describes, are, ]. The galeiis mus- 

 lelus, the squalus mnstelns of Liniifcus. The specimen examined 

 was caught in the Frith of Forth. 2. The squalus selanonus, 

 from a dried specimen in the Museum of the University of Edin- 

 burgh, caught in Lochfyne, and described by the late l)r. Walker. 



6. An Essay on Sponges, with Descriptions of all the Species 

 that have been discovered on the Coast of Great Britain. By 

 George Montagu, Esq. F. L, S. and M. W. S. — This is a very curious 

 and elaborate paper ; but from its nature, scarcely susceptible of 

 useful abridgment. Mr. Montagu considers sponges as animals 

 destitute of all motion, and possessed of organs of digestion similar 

 to tho>e of plants ; in short, they are plants as to structure and 

 properties^ but tliey are of an animal nature ; because, when dis- 

 tiilcd, they yield tlie same products with other animal bodies. He 

 gives a description of no fewer than 39 species of British sponges. 

 Only 14 species were previously known, so that he has nearly 

 tripled the list. I wish he had been at the trouble to make his 

 title grammatical. He has made it Spongia Britaniuca, instead of 

 Spongiie Britannicse, which is the true title. 



7. A4ineralogical Description of Tinio. By Dr. Macknight. — 

 Tinto is a mountain in Lanarkshire, about 2300 feet above the level 

 of the sea. According to Dr. Macknight, it is composed of fioetz 

 rocks, which, probably, rest upon grey-wacke, of which the 

 neighbouring hills are composed. The lowest bed is a conglo- 

 merate, having a basis of clay, with a dark greyish colour, and 

 somewhat resembling an intimately mixed green-stone. Tiie frag- 

 ments it contains are water-worn masses of transition rocks, as 

 grey-wacke, grey-wacke-slate, iron-clay, and common flinty-slate, 

 with veins of quartz. There arc also nodules of quartz, mica, 

 felspar, splintery horn-stone and felspar, passing into conchoidal 

 horn-stone. Over this conglomerate, which constitutes the base of 

 the mountain, masses of clay-stone, green-stone, and green-stone 

 pas>ing into elink-sione and porphyry-slate, successively appear, 

 till we anive at the sunmiit of the mountain, which consists of 

 compact fcls])ar, and felspar porphyry. These diii'erent rocks pro- 

 bably constitute so many beds '>Kt tl»e point was not ascertained. 



a. stunt Account oj the lUxlts ivhich occur in the Neighbourhood 

 of DiiiuUc. By tlic Rev. John Fleming, Flisk. — These rocks are 

 all flue:/. A j>orphyry with Inise of compact felspar alternates with 

 • ' le, w(st from Dundee ; and the sand-stone fills up several 

 1 ' in tbe porphyry, i'urlher east, rocks of green-stone and 



day-stone appear, and the grecii-stonc seems to pass into clink- 

 •(unc. 



