148 
NOTES AND MEMORANDA. 
A Test Object for Histologists. — Professor Eanvier recommends as a 
test for objectives intended for histological work (“ which are required 
not for flat bodies presenting only fine striae, but for objects of 
irregular and varying forms, rough, concave, or convex ”), the isolated 
muscular fibrillae of the wings of the Hj/drophili. With a power 
exceeding 300 diameters, the alternately thick and thin dark disks 
which characterize the fibrillae may be seen. 
On the Bhizopoda of the Salt Lake of Szamosfalva. — Dr. G. Entz 
has described the Rhizopoda obtained by him from a salt pool at 
Szamosfalva, near Klaiisenberg, in Hungary. He procured in all 
twelve species, five of which, all shelled species, are described as new, 
and two of them as the types of new genera. These are Pleuro- 
pliri/s helix, Plectrophrys (g. n.) prolifera, Eiiglypha pusilla, Micro- 
cometes tristrypetiis, and Orbulinella (g. n.) smaragdea ; the other forms 
noticed are CiUophrys infusionum, Cienk., Podostoma filigerum. Clap, 
and Lachm., and five species of Amoeba. 
The majority of the Rhizopods belong to forms which are very 
common in fresh water, but which must probably be referred to the 
category of organisms which occur indifferently in both fresh and salt 
water ; and, so far as this supposition applies to the Amoeba, Dr. Entz 
furnishes a confirmation of it in a subsequent short note, in which he 
states that he found Amoeba Umax and A. radiosa very abundantly in 
sea-water from Cuxhaven. (He regards the marine forms A. marina, 
Dnj., A. polypodia, F. E. Schulze, and possibly also Protmoeba 
polypodia, Hack., as probably identical with A. radiosa.) 
Of the forms jDeculiar to the Szamosfalva salt-pool, two (namely, 
Euglypha pusilla and Microcnmetes tristrypetiis) find their nearest rela- 
tions in fresh-water organisms. Pleurophrys helix, on the contrary, 
belongs to a marine type. Of the two new genera, Orbulinella is the 
most nearly related to the marine perforated Foraminifera, and 
Plectrophrys is referred to the neighbourhood of Pleurophrys, Pla- 
giophrys and Chlamydophrys, and may be either a marine or a fresh- 
water type. As a negative character bearing on the marine or 
fresh water affinities of the Rhizopodal fauna of Szamosfalva, the 
author remarks on the total absence of Arcellce and Difflugice, both of 
which are so abundant in, and characteristic of, fresh water.* 
The Conversazione of the Boyal Society on May 1. — The following 
objects of interest to microscopists were exhibited : — Dr. Woodward’s 
rectangular prism illuminator, to be used with immersion lenses ; 
and Dr. Edmunds’ immersion paraboloid (exhibited by Mr. J. 
Mayall, jun.). A new form of micro-spectroscope, exhibited and 
made by Mr. Adam Hilger on a plan suggested by Mr. Sorby. 
Instead of placing the lens used to focus the slit below the prisms, 
it is placed just above them, and a cylindrical lens is fixed below, in 
order to correct the astigmatism. The advantage of this arrangement 
is that the whole apparatus is very greatly reduced in length ; in 
fact, to about half the usual size. The lens used to focus the slit 
also serves to focus a graduated scale seen by reflection over the 
spectrum, which enables the observer to measure at once the position 
* Hungarian ‘ Naturliistoriselie Hefte,’ 1877, 3 and 4; ‘Ann. Nat. Hist,,’ 
May, 1878. 
