HA RD WICKE ' 5 ^ CIENCE- G OS SIP. 



^00 



Pseudopodia extended. Fig. 94, very fine speci- 

 men from Sphagnum ; test of extra large and rough 

 sand-grains. Size 35 of an inch. Diffliigia glohidosa 

 is another common form, one of the smallest of the 

 genus. It was one of the first to be described and 

 figured, and is probably the D. protdformis of the 

 illustrious Ehrenberg. Its general form is that of a 

 round or oval box, more or less truncated at the 

 mouth. One common variety has exactly the form 

 of the * box ' of the sea urchin (Echinus). In the 

 character of the materials used in the formation of 

 the test, and in other particulars, it differs little from 

 the preceding. I occasionally come across a form in 

 several of our shaded wells and clear pools, which 

 has a large, eccentric mouth, like D. constricta, or 

 the spineless form of Contropyxa aacleata. As it 

 is too low for the former, and is wanting in the 

 appendages to the incurved mouth of the latter, it 

 more properly, I think, may be placed here. Size 

 from jJjj to :iJj^ of an inch. 



Fig. 95. Empty test, made up of minute sand- 

 grains ; ventral view. 



Fig. 96 of chitinoid membrane, with scattered large 

 sand-grains. Side view, pseudopodia extended. 



Fig. 97. This form might, with almost equal 

 propriety, be classed with D. constricta, or even 

 with Centropyxis ecornix, as the mouth is eccentric, 

 and the highest part of the shell behind the mouth ; 

 but it appears to me, for reasons given above, to 

 have a greater affinity to the present species. 



Fig. 98. Side view of specimen with closely- 

 packed sand-grains. 



Fig. 99. The same, rolled over to show the 

 mouth of the shell. 



Difflicgia aciiviitiata is also an equally common 

 form here, and I procure it in considerable numbers 

 from among Sphagnum in boggy places, and in most 

 of our shady wells and clear pools. The prevailing 

 form is shown in Fig. 100. The species mayjbe 

 described as pyriformis, drawn out to a point at the 

 top (fundus). 



The test is oblong oval, in the typical form, 

 narrowing towards the mouth, and more or less 

 suddenly tapering towards the summit, in varying 

 degrees of acuteness. Although this species is as 

 variable as any in the genus, I have only as yet 

 found two well-marked varieties, during the three 

 months I have been specially studying the Rhizopods. 

 Like the preceding species, the test is made up of 

 sand-grains, occasionally intermixed with the frustules 

 of diatoms, or it is obviously of chitinous membrane, 

 either colourless or yellow, more or less incrusted 

 with the above elements, sometimes very irregularly 

 so. Size from >^-^ to ^Ij of an inch. Barcode rarely 

 coloured. 



Fig. 100. The prevailing form in this district, of 

 colourless chitinoid membrane, with scattered sand- 

 grains and diatoms. Pseudopodia extended. 



Fig. loi. Large specimen, from shaded well, test 



of yellow, wrinkled chitine, with large sand-grains 

 and a few linear diatoms. The sand and diatoms do 

 not project much, but are apparently sunk in the 

 membrane, and so partake of its yellow colour. In 

 my next I shall treat of the box-like Gentropyxis, and 

 the genus Arcella. The latter is one of the 

 commonest forms of the Rhizopods, and is the one 

 most frequently noticed by microscopists who do- 

 not make a special study of the class. 



Diffliigia iirceolata is a large variable form closely 

 related to D. acuminata. The shell is somewhat 

 ovate, amphora-like ; fundus either evenly rounded 

 or more or less acute, frequently furnished with 

 blunt spines. Neck short ; mouth large and round, 

 occasionally with a reflected rim. 



This handsome species is of rare occurrence iri' 

 this district, and when I do find a specimen it has 

 generally been an isolated one. My specimen has an 

 acute fundus, and the neck is only slightly reflected. 

 Size about ,lg inch. The test is of sand grains — a few 

 large ones, regularly distributed, the intervals filled, 

 up with smaller ones of nearly equal size (Fig. 104). 



J. E. Lord. 



Rawtenstall. 



NOTES ON NEW BOOKS. ' 



TX/TEMOIR OF SIDNEY GILCHRIST 

 IVl THOMAS, by R. W. Burnie (London : 

 John Murray). This is altogether a noble, bright,, 

 and cheerful book — the pleasant record of a brilliant 

 young life. The " Thoman-Gilchrist " process, by 

 which formerly half- worthless iron ore is converted into 

 good stuff, by having its phosphorus extracted, whilst 

 the latter in its turn is utilised as artificial manure— - 

 is already well-known to most of our readers. Only 

 thirteen years ago there was not in existence any 

 public record of the successful dephosphorisation of 

 pig-iron — last year there were 2,603,083 tons pro-- 

 duced. In addition, last year there were placed on 

 the market, to be used as artificial manure — stones- 

 that science has converted into bread — no fewer than 

 623,000 tons of basic slag. This wonderful success 

 in metallurgy was due almost solely to the patience 

 and unwearying industry of Sidney Gilchrist Thomas,. 

 and yet he died (of overwork, it is to be feared) at 

 the early age of thirty-four. By that time he had 

 come to be acknowledged as the most brilliant 

 metallurgist of the century. Honours from all. 

 countries were showered thickly upon him. And yet 

 this scientist left school at seventeen to be a school- 

 teacher. At eighteen he was clerk in a London> 

 Police Court, an ofifice he held for twelve years. He 

 studied chemistry, mineralogy, geology, &c., on^ 

 what leisure evenings he had, and conducted his 

 experiments and investigations then and during his. 

 holidays. He made his valuable discovery whilst 

 still a clerk at the Thames Police Court. Within 

 the brief period of a twelvemonth we find him a 



