276 



HARDWICKE'S SCIENCE-GOSSIP. 



by Captain Perry, of Liverpool. The following are 

 the forms described : — Pemja, n. g., forms some- 

 what resembling Nitzscliia;, but are distinguished 

 from that genus by the absence of the more or 

 less marginal keel. The species figured (P. pul- 

 cliernma) resembles an Indian canoe, the scales of 

 which are much compressed and marked with dis- 

 tant transverse moniliform lines not reaching the 

 edge ; between these lines are transverse series of 

 fine moniliform strife. It sometimes exceeds one- 

 fiftieth of an inch ni length. Nitzschia rjrandis, n. s. 

 This is probably one of the most beautiful of the 

 genus. The valve is linear, broad, suddenly taper- 

 ing towards the incurved apices ; keel sub-central, 

 costate, punctate between the costse; remainder 

 of valve marked with transverse moniliform 

 stria;. Length from -0100" to -OSOO". The 

 most magnificent form detected in this gather- 

 ing was a seven-angled Triceratinm witli large 

 hexagonal cells ; the internal surface of valve 

 marked with conspicuous radiating puncta. From 

 observations on broken valves, the author con- 

 siders that the valve has a thin siliceous plate 

 attached to its inner surface (a very early state of a 

 new valve), upon which occur the radiating puncta, 

 seen when the lower surface of the valve is in focus. 

 Mr. Kitton has named the form Tricemtmn Faviis, 

 var. sept-angulatum. A new species of Surirella 

 was found in a deposit from New Zealand, which 

 the discoverer thus describes : Surirella contorta, n.s. 

 Valve elliptically or slightly ovate, canaliculi fine, 

 numerous ; alse inconspicuous, narrow median eleva- 

 tion terminating in short spines ; surface of valve 

 obscurely striate ; valve in front view contorted. 



QuEKETT Microscopical Club.— The October 

 number of the Journal of this celebrated club has 

 just been published, and as usual contains several 

 very useful and excellent papers. The most note- 

 worthy are two of a series by Dr. Braithwaitc, on 

 the " Histology of Plants," and one by E. T. New- 

 ton, E.G.S., of the Jermyn-street Museum, on the 



"Preparation of Microscopic Sections of Soft 

 Tissues." There are also papers on " How to make 

 Thin Cover Glass," by G. J. Burch ; on a "Ealse 

 Light-excluder" for objectives, by J. E. Ingpen, 

 Hon. Sec. ; on the " Development of Hydra 

 vulgaris" by James FuUagar ; and a paper on a 



" New Perm of Section-cutting Machine for the 

 Microscope," by Dr. Hoggau. 



The Derbyshire Microscopical Society. — The 

 Monthly Meeting of this Society, which now at the 

 close of the second year of its existence, numbers about 

 forty members, was held in Derby on Thursday even- 

 ing, their)th ult., the Rev. J. M. Mello, M.A.,P.G.S., 

 President of the Society, in the chair. The Presi- 

 dent read a paper on " Microscopical Geology," in 

 which he called attention to the great importance 



to the geologist, as well as the mineralogist and 

 petrologist, of an intelligent use of the microscope 

 in their investigations. It was shown that by its 

 means, in conjunction with thepolariscope,itwas pos- 

 sible to discriminate between the various minerals 

 which enter into the composition of rocks, even 

 when these minerals take the most minute forms, but 

 that it was possible also to arrive at tolerably clear 

 notions regarding the history of the formations of 

 the rock, and of the individual crystals when pre- 

 sent, of which it is composed. It was also shown 

 how much service the microscope rendered in the 

 investigation of the minuter organisms in rocks, 

 many of which were undiscoverable by the naked 

 eye. In a similar way small fragments of a bone, 

 or of a tooth, might be found sufficient to enable 

 the skilled observer to trace its affinities, just as an 

 examination of coal by the microscope had been the 

 means of throwing a large amount of light upon the 

 nature of the plant-life of bygone ages. In the 

 course of the paper the microscopical characteris- 

 tics of the minerals most commonly met with in the 

 igneous rocks were pointed out, and the whole sub- 

 ject was illustrated by diagrams and by a very ex- 

 tensive display of rock and mineral sections under 

 the microscopes of some of the members present. 



Re Society's " Universal Screw." — Mr, 

 GuimaraenSjOr any one in doubt as to the accuracy 

 of the so-called Universal Screw, of either object- 

 glass or microscope nosepiece, has but to apply to 

 Mr. Reeves, at the Royal Microscopical Society's 

 rooms, and he, with his usual courtesy, will test it 

 with the screw gauges deposited with the Society, 

 which gauges are not likely to have altered from 

 use, as are those of the optician, although in the 

 latter case there is still the formula for their re- 

 adjustment. 



ZOOLOGY. 



A Variety op Land-shell New to Britain. — 

 I have been fortunate enough during the last few 

 months to find a new and distinct variety of Clausilia 

 rngosa, the peculiar characteristics of which were 

 first noticed by G. SherriffTye, Esq., of Handsworth, 

 and which has since been kindly determined for me 

 by J. Gwyn Jeffreys, Esq., E.R.S. I send a de- 

 scription of them, as also the remarks made upon 

 this new and rare variety by the same eminent 

 authority, who has kindly favoured me with his 

 opinion respecting them. He considers it to be the 

 variety Schlechtii, of Zelebor, whose description of 

 it is published in the monograph of Adolf Schmidt, 

 entitled "Die Kritischen Grappen der Europiieschen 

 Clausilien," lSo7, page 40. " Claus. dubia Dra- 

 parnaud g. var. Schlechtii. Zelebor, gracilis^ 

 cerasiora, nUidula, striafula, rarc-strigillata, carina 



