152 MR. E. HERON-ALLEN ON SKIAGRAPHS OF FORAMINIFERA. 



1 Squirrel- Monkey (Saimiris sciurea), from Demerara, and 

 1 Potto (Potos caudivolvulus), from Colombia, presented by 

 Gordon R. W. Hutton on January 27th and 31st. 



2 Senegal Genets {Genetta senegalensis), from Zaria, Nigeria, 

 presented by Charles Migeod on January 19th. 



1 Peter's Spotted Fire- Finch (Lagonosticta niveiguttata), from 

 E. Africa, new to the Collection, received in exchange on January 

 11th. 



The Application of X rays to Microscopical research ; illustrated 

 by Skiagraphs revealing the internal structure of Foraminifera. 



Mr. E. Heron- Allen, F.L.S., F.Z.S., brought before the Society 

 a new method of determining the internal structure of the 

 Foraminifera without transparent mounting or section-cutting, 

 or other interference with the specimens, by means of Skiagraphs. 

 These have been made by Mr. J. E. Barnard. A series of slides 

 was exhibited showing : — (i.) The first experiment made for the 

 purpose of ascertaining the structure of a Foraminifer of a new 

 type, and of extreme rarity found in the Kerimba Archipelago 

 (E. Africa), (ii.) An ordinary North Sea dredging showing the 

 internal structure of the Foraminifera as if they had been mounted 

 in balsam, (iii.) Thick and dense tests of Massilina secans 

 (d'Orbigny) and Skiagraphs of the same, (iv.) The still thicker 

 and denser tests of Biloculina bulloides d'Orbigny, the Skiagraphs 

 showing the arrangement of the earlier chambers, (v.) Comuspira 

 foliacea (Philippi). The dense imperforate shells, and Skiagraphs 

 revealing micro- and megalo-spheric primordial chambers, (vi.) 

 Coarse and densely agglutinate tests of the arenaceous species 

 Astrorhiza arenaria Norman, and Skiagraphs revealing the cavi- 

 ties containing the protoplasm body, (vii.) Two monothalamous 

 arenaceous types of similar external appearance. The Skiagraphs 

 reveal that one is Botellina labyrinthica Brady, and the other 

 Jaculella obtusa Brady, (viii.) The dense hyaline tropical species 

 Opercidina complanata Defrance, with the obscuring papilla? 

 constituting the var. granulosa of Leymerie, the Skiagraphs 

 revealing curious distortions of some of the internal septa, (ix.) 

 The equally dense species Orbiculina adunca (Fichtel & Moll), the 

 central chambers obscured by thick shell-growth which does not 

 affect the Skiagraph, (x.) The coarse and solidly built arena- 

 ceous species C'yclammina cancellata Brady, the dense cement shell 

 studded with sandy particles. These disappear in the Skiagraph, 

 which shows the labyrinthic structure and a megalospheric 

 primordial chamber, (xi.) A Nodosarian, showing the method of 

 growth by the addition of successive chambers. [From (vi.) to 

 (xi.) were shown in two states, (a) in black on a white ground 

 and (b) reversed.] (xii.) The common tropical form Orbitolites 

 complanata Lamarck, the Skiagraphs showing the Milioline early 

 chambers. Shells of this species were also exhibited which had 



