HARDWICKE'S SCIENCE-GOSSIP. 



21 



hood of St. David's, from the base of the Cambrian 

 to the top of the Tremadoc group, and showed that 

 they there form an unbroken series. The only break 

 or unconformity Recognized is at the base of the 

 Cambrian series, where rocks of that age rest on 

 the edges of beds belonging to a pre-Cambrian 

 ridge. In the second part the author gave a minute 

 description of the rocks, comparing the Arenig and 

 Llandeilo groups, as seen in Pembrokeshire, with 

 each other, and also with ' those known in other 

 Welsh areas. Each group he divided into three 

 subgroups, chiefly by the fossil zones found in them. 

 1. The Lower Arenig was stated to consist of a series 

 of black slates about 1,000 feet thick, and to be 

 characterized chiefly by a great abundance of den- 

 droid graptolites. 2. Midde Arenig. A series of flags 

 and slates, about 1,500 feet thick and with the follow- 

 ing fossils : — Ogygia scutatrix, O. peltata, Ampyx Sal- 

 ter i, &c. 3. Upper Arenig. — A series of slates, about 

 1,500 feet in thickness, only recently worked out, 

 and found to contain a large number of new and 

 very interesting fossils belonging to the following 

 genera ; viz. Illcenus, Lllcenopsis, Placoparia, Bar- 

 randia, &c. 4. Lower Llandeilo. A series of slates 

 and interbedded ash, equivalent to the lowest beds 

 in the Llandeilo and Builth districts, and containing 

 species of JEglina, Ogygia, Trinucleus, and the well- 

 known graptolites Didymograpsus Mv.rchisoni and 

 TJiplograptus foliaceus, &c. 5. Middle Llandeilo. 

 Calcareous slates and flags with the fossils Asaphus 

 tyrannus, Trinucleus Lloydii, Calymene cambrensis, &c. 

 6. Upper Llandeilo. Black slates and flags, with 

 the .fossils Ogygia Buchii, Trinucleus fimbriatus, &c. 

 The Arenig series was first recognized in North 

 Wales by Prof. Sedgwick about the year 1843, and 

 was then discussed by him in papers presented to 

 the Society. The Llandeilo series was discovered 

 by Sir R. Murchison previously in the Llandeilo 

 district, but its position in the succession was not 

 made out until about 1844. The Geological Survey 

 have invariably included the Arenig in the Llandeilo 

 group ; but it was now shown that this occurred 

 entirely from a mistaken idea as to the relative posi- 

 tion of the two series, which were proved to be 

 entirely distinct groups, the equivalents of both 

 groups being present in Carnarvonshire, Shropshire, 

 and Pembrokeshire, but the Llandeilo group only 

 of the two being developed in Carmarthenshire. 

 The lines of division in the series were said to be 

 strongest at the top of the Menevian group and at 

 the top of the Tremadoc group, these lines being 

 palseontological breaks only, and not the result of 

 unconformities in the strata. 



NOTES AND CtUEItlES. 



Trees Springing out op Enclosed Tombs.— 

 Seeing some instances of the above in Science- 

 Gossip, I thought it might interest some of your 

 readers to know of an instance I have come across. 



In Einchley Churchyard there are two trees (or 

 rather bushes), and to the best of my recollection 

 they are elders, which grow out of enclosed tombs ; 

 the tombs are the kind built of brick with a stone 

 slab on top, and are enclosed by iron railings. One 

 of the bushes has twined round an iron rail and the 

 iron was, when I saw it, embedded for about six or 

 seven inches of its length in the stem of the bush. 

 The stems of both appear to spring from mere 

 crevices between the bricks, and the bricks have 

 been but very slightly displaced. The seeds, I sup- 

 pose, were carried into the crevices and there took 

 root. The largest of the bushes was about eight or 

 ten feet high and overshadowed the whole tomb. — 

 B. T. Evans. 



Butomus tjmbellattjs.— Under this heading in 

 Science-Gossip, p. 262, for November, Mr. D. Roe- 

 buck records its being found very late in flower at 

 Kirkstall, and I presume, from what he says, that it 

 is rather scarce. My object is to point out a station 

 which has probably been overlooked. Sixteen years 

 ago I lived in Leeds, and one summer, I think within 

 the time he names, I found Butomus on the right or 

 south bank of the Leeds and Liverpool canal, about 

 30 yards above the last lock before coming to Armley: 

 it was growing in company with Sagittaria. The 

 latter was abundant ; but I cannot say so much of 

 the former. When the season comes round, I would 

 recommend Mr. R. to look out for it, as I think the 

 station was not likely to be improved away or built 

 upon. — /. Maughan, Barnard Castle. 



Preserving Marine Alg^e. — Amongst the 

 many classes of material for micro objects that I 

 collect for microscopists, I am often asked for a col- 

 lection of marine algae for mounting, but lind a very 

 great difficulty in preserving them properly for 

 microscopical purposes, as, if once dried, they become 

 unfit. Many kinds, such as Cladopkora, in variety, 

 and Ceramium, &c. &c, do well in glycerine, but 

 others, of softer texture, and especially fruited speci- 

 mens, lose their colour or burst. I should feel glad 

 to know how I could overcome this difficulty. I 

 should also be much obliged by a few hints on the 

 best way of collecting foraminifera living in rock 

 pools. Erom the quantity found on many of the 

 beaches here, I have no doubt they are very abundant 

 in the Bays (Connemara). — T. McGann, Burrin, 

 Ireland. 



Staining Vegetable Tissues. — An article on 

 this subject in the last Gossip reminded me of an 

 unsuccessful attempt to stain a different substance 

 — native coral. — I am not geologist enough, nor suf- 

 ficiently scientific, to be able to state the component 

 parts of this article, — probably lime;— but whatever 

 it may be, after trying several dyes, even Judson's, 

 1 could not fix any colour permanently. Perhaps 

 some of your readers may be able to give a receipt. 

 — W. H. B. 



Toad and Spider. — An acquaintance of mine 

 gave me the following anecdote :— One day, as he 

 was standing in a farmyard, he observed a toad 

 attempting to enter the barn by crawling beneath 

 the door, and when in the act, a spider descended 

 the door and alighted on the toad's back, which it 

 apparently bit. The spider then ascended the door, 

 and the toad retraced its steps to a plant, the 

 "waytre" (Plantago major), which was growing a 

 few feet distant from the barn, and partook a little 

 of its leaf. The toad then made another attempt as 

 before to get into the barn, and was again pounced 

 upon by its vigilant foe. The toad, with all speed 



