276 



HARDWICKE'S SCIENCE-GOSSIP. 



localities. It is fan-shape in character; but the 

 branches of specimens from Richmond, in Yorkshire, 

 differ materially from those found in North Wales. 

 It often presents two different characters in well- 

 developed fronds— so much so that if a good frond was 

 broken and distributed to several Paleontologists, 

 asking them to identify the species, two sets of 

 opinions would be the result. F. frutex, M 'Coy, seems 

 to be a good species, so also are the F. polyporata, 

 and the F. wididata, of the same author; but 

 F. nodulosa, and F. temdfila, are somewhat doubtful. 

 The F. formosa, of M'Coy, is also doubtful in the 

 character of the poriferous dissepiment; but the 

 F. plebeia, F. quadradecemalis, and the F. carinata, 

 of the same author, have pretty constant characters. 

 The F. crassa, and F. ejuncida, are doubtful. The 

 F. hemispherica is a beautiful specimen, but may it 

 not be the young form of some of the larger specimens 

 described as species ? Besides these forms there are 

 several others in my list, but after having examined 

 many of the fine species gathered by Mr. Shrubsole 

 from the Halkyn Mountains of North Wales, I am 

 rather in favour of a reduction than of an extension 

 of species. My belief is that many of the so-called 

 species are the result of indiscriminate grouping. The 

 fault of the confusion, is not so much pressed home 

 upon the describer as upon the collector. It may be 

 that no Fenestella bands have been so well preserved as 

 are those of the Halkyn Mountain group ; and it may 

 be that collectors have been more careful for general, 

 than for particular fossils. Be that as it may, the 

 group well deserves revision, and having a sufficient 

 knowledge of the material at his disposal, I believe 

 the work will be well and honestly done by Mr. 

 Shrubsole. 



The Fenestella of the Permian rocks are few in 

 number— both as regards species and individuals. 

 The form generally met with in collections is 

 F. reticularis, of Schlol. In Morris' Catalogue this 

 is given as F. retiformis, with the synonyms Kerato- 

 phytcs, Gorgonia infundibuliformis, Goldfuss, and 

 Rctcporajlustracea, Phillips, but as my own specimens 

 show only the non-poriferous side, I am unable to 

 give any minute details respecting the species. The 

 non-poriferous aspect bears a close resemblance to 

 some of the Carboniferous, and also of the Silurian 

 Fenestella ; dependence, however, upon this is unsafe 

 as a palseontological guide. 



In space this genus had a remarkably wide range ; 

 it being tolerably abundant in the Paleozoic series of 

 America. In this country the foregoing remarks will 

 justify my assertion that it was also abundant with 

 us. De Koninck and others have shown how preva- 

 lent certain species are in the Bohemian and Belgian 

 series, some of the species belonging to the latter 

 extending as far east as India. In time the genus 

 ranged throughout the whole of the Paleozoic rocks, 

 becoming extinct, so far as is yet known, at the close 

 of the Permian era. 



MICROSCOPY, 



Varnish for Glycerine Mounts.— Some time 

 since I asked in Science-Gossip for some varnish 

 which would not be affected by glycerine jelly. No 

 satisfactory answer being given, I had to fall back on 

 my own experiments, and am glad to say I have at 

 last found a varnish, which, worked with others, 

 answers in the best possible manner. The varnish I 

 allude to is gold size, and I find the following method 

 of applying it answer best. Having mounted your 

 slide, and allowed time for the glycerine to set, go 

 carefully round the thin glass circle with a warm pen- 

 knife, then with a fine camel's-hair brush run a ring 

 of gold size round, by means of the turn-table ; allow 

 this to dry, then apply another layer, and when this 

 is dry a third ; lastly, run a ring of white lead varnish 

 over the gold size, and finish with a ring of green 

 varnish in the centre of the white if your object be 

 a vegetable preparation, or red, if it be animal. I 

 have mounted some dozens of slides in this way, and 

 in no case have I so far found the varnish to fail. 

 Let me recommend readers of Science- Gossip, who 

 like myself have had a difficulty in finding a stable 

 varnish, to give this method a fair trial. Dr. Car- 

 penter in his work, "The Microscope," it will be re- 

 membered, speaks highly of gold size as a varnish. 

 I consider, however, that without some varnish over 

 it, gold size does not make a very neat or a very 

 elegant appearance.— Charles F. W. T. Williams, 

 the Vicarage, Tinslade, Bucks. 



New Diatoms. — Melosira Barren (Grev.) var. 

 Hispida Castracane. This variety is distinguished 

 from the type form by the presence of short teeth or 

 spines scattered over the surface of the valves, but 

 especially on the lower convexity of the frustule. 

 Canal de Trau, Dalmatia, Cyclophora, n.g. 

 Castracana, frustules tabular, rectangular, sometimes 

 in series, sometimes free, sometimes connected by a 

 gelatinous isthmus forming a zigzag chain in f.v. 

 linear-oblong, sometimes slightly inflated, valves 

 unequal, one of them with a central loculus, living in 

 sea-water. Cyclophora tenuis, Castracane ; frustules in 

 f.v. oblong, rectangular, slightly inflated, valves linear, 

 inflated, rounded at the ends, dissimilar, one of which 

 has a central ring or loculus. Length of valve, 

 441" 5, 55/*. 2 > breadth 4/1 8, ii/t 3. On rocks at 

 Ancona ; Naples, in aquarium. (Extracted from 

 Brebissonia, a new monthly serialde voted to Algeology 

 and Micrographic Botany, edited byM. G. Huberson. .). 



Diatoms in Coal.— It is, perhaps, in the recol- 

 lection of our readers, that about two years ago,. 

 Count Castracane announced the discovery of marine 

 and fresh-water diatoms in coal ashes. Professor 

 W. C. Williamson, at the Dublin meeting of the 

 British Association, doubted the accuracy of this, and 

 stated that Professor Roscoe had permitted one of 



