T 3 6 



HARDWICKE'S SCIENCE-GOSSIP. 



20. Schizonema, Agardh, 1824: Strahlenschiffchen. 



21. Striatella, Ehrenberg, 1835: Zickzackfahnchen. 

 Diatoma in part, Decandolle, 1815 ; Fragilaria in 

 part, Lyngbye, 1819; Achnantlies'm^zxi, Carmichael, 

 1827. 



22. Syncyclia, Ehrenberg, 1835 : Ringschiffchen. 



23. Synedra, Ehrenberg, 1836: Ellenthierchen ; 

 Vibrio in part, M tiller, 1786; Diatoma in part, 

 Graveloup, 1806; Bacillaria in part, Nitzsch, 1S17 ; 

 Echinclla in part, Lyngbye, 1819 ; Friistulia in part, 

 Agardh, 1824; Exilaria in part, Kutzing, 1833; 

 Fhabdium in part, Wallroth, 1833 ; Conferva in part, 

 Vahl, 1792; Lunulina in part, Bory? 1824. 



24. Tessella, Ehrenberg, 1835 : Plattenkette ; Dia- 

 toma in part, Hornemann, 181 2; Striatella in part, 

 Agardh, 1832 ; AchuantJies in part, Kutzing, 1833. 



Number of species, 144. 



Doubtful genus, Microtheca. 



In the above genera are comprised all those pre- 

 viously observed, of which Ehrenberg abolishes 35, 

 two of which have been re-established by other 

 Diatomists. 



In 1844 Kutzing and others increased the number 

 of genera to 69, and the species to 7S4. 



The number of genera now probably exceeds the 

 number of Ehrenberg's species in 1838, and the 

 species may be reckoned by thousands. 



MICROSCOPY. 



Estuarine Foraminifera. — In the estuary of 

 Lough Foyle, County Londonderry, I have dis- 

 covered a deposit of estuarine clay, extremely rich in 

 foraminifera. One grain of the floatings has been 

 found to contain as many as 10,000 individuals. My 

 friend Mr. Joseph Wright has examined the float- 

 ings, and he has already detected about 90 species, 

 including nearly all the British Lagenas, and many 

 other species, that are by no means common else- 

 where. I shall be glad to distribute some floatings 

 among any correspondents who may desire it. — 

 William Gray. 



Preserving Fluid. — In the recipe given on 

 page 87 one of the ingredients is "Mefhylic alcohol." 

 This is, I believe the chemical name of wood naphtha. 

 I should be glad to learn whether this or ordinary 

 methylated spirit of wine is the article to be used, 

 and also whether or not the fluid has been tried by 

 any of the readers of Science-Gossip. — IV. G. Tux. 



Preservation of Living Objects and their 

 Examination under the Microscope. — We are 

 glad to see that Mr. Thomas Bolton, F.R.M.S., has 

 republished the articles on the above subject from the 

 " English Mechanic," in the form of a small pamphlet 

 which may be obtained from the author, 17 Ann 

 Street, Birmingham, price threepence. It contains 



short articles on the following subjects : "Examina- 

 tion of Objects attached to weeds and root fibres, 

 such as Polyzoa, Hydra," &c. " Examination of 

 free-swimming Rotifers, Infusoria," &c. "A short 

 Summary of the most useful Apparatus," &c. 



A New Collecting Bottle. — Hoping to aid 

 those who may at this season be seeking for pond 

 life, I send a sketch of a collecting-bottle that I have 

 just devised and find very excellent. You will at once 



Fig. 85.— New Collecting Bottle. 



a, Wide mouth bottle ; b, Glass tube with muslin tied over the 

 bottom ; c, Glass funnel both fitting tight in a good cork ; the 

 action will at once be seen. 



see that its success is due to filtration by ascension. 

 The weeds may be swept with any convenient vessel 

 (I use a flat photographic dipping bath, as it presents 

 more surface) and emptied into the bottle so long as 

 may be desired. — Fred. Row. 



Dull Objectives.— I think Mr. Walter G. Wooll- 

 combe has over-cleaned his \ inch objective, and this 

 may be the reason of its increasing dulness. He 

 says he has rubbed it with chamois leather. This is 

 enough to spoil any good objective ; let him shake his 

 chamois leather and see the dust which will come from 

 it. The glass of a really good objective is very soft 

 and most easily scratched. If an objective wants 

 cleaning, use nothing but a very old and well-worn 

 silk handkerchief, which must be very clean. Many 

 good lenses are ruined by injudicious cleaning. — 

 IV. C. Penny. 



Pond Life in the Parks. — Microscopists seek- 

 ing for Rotatoria, would do well, before going 

 further afield, to examine a little water from some of 

 the lakes in London parks. I have lately (April) 

 found several good things in the Serpentine, amongst 

 which were Triarthra longiseta and Polyarthra 

 platyplera, two of the leaping rotifers. I have also 

 met with the male of Brachionns urceolaris in 

 abundance from the same source. Floscularia and 

 Limnias are common on the weeds. Doubtless many 



