290 rORAMlNIFERA OF THE CRAG. 



Occiirrence. — Spirillina vivipara (with its varieties) has a world-wide distribu- 

 tion in comparatively shallow waters. The lowest depth from which specimens 

 were obtained by the ' Challenger ' was 620 fathoms. 



Fossil specimens are comparatively rare. It has been obtained from the 

 Miocene of Vienna and Lower Bavaria, the Pliocene of St. Erth, and the 

 Pleistocene of Ireland. In the Coralline Crag we have specimens of the type-form 

 or varieties from nearly every zone examined. Fig. 22 represents a specimen 

 from Broom Hill. Dr. Schacko describes his Sp. minima as being abundant in 

 the Chalk of Rugen. 



1**. Spirillina vivipara, Ehrenberg, 1841, var. complanata, nov. Plate III, 



figs. 20—22. 



Part I, 1866 (" Spirillina vivipara "), Appendices I and II, Tables, No. 75. 



In figs. 20 — 22 we see all the chai'acters of Spirillina vivipara excepting that 

 the edge is obliquely steep, — that is, the tube, instead of being circular in section, 

 has an obliquely oblong sectional area, and the shell is flat above and below, the 

 sutures being quite flush with the surface, and the whorls not at all overlapping 

 one another. 



Hence we must regard this figured specimen as a variety (var. complanata). 

 The oblique periphery is seen also in Bi'ady's Sp. insequalis, Rep. ' Challenger,' 

 p. 681, pi. Ixxxv, figs. 8 — 11. 



Occurrence. — For that of the type-form see above. The figured specimen 

 (PI. Ill, figs. 20—22) was collected by Mr. S. V. Wood in the Sutton Crag. 



Suh-family 2.— Rotaltn^. 



Test free or, rarely, attached, somewhat ammonitiform (rotaliform), and some- 

 times acervuline. Aperture usually or normally a crescentic slit on the inferior 

 face of the shell. 



Genus 1. — Discoebina, Parker and Jones, 1862. 



Carpenter, 1862, Introd. Foram., p. 203 ; Brady, 1884, Report ' Challenger,' 



pp. 72, 627, 640. 



RoTALiTES, Lamarck, Defrance, Blainville. 



RoTALiA, Lamarck, d'Orhigny, von Mimster, JRBmer, Michelotii, Parker and Jones, 



Morris and Quekett. 

 DiscoBBis, DiscoEBiTES, Lamarck, Defrance, Blainville, Bertlielin. 



