OF FORAMINIFERA FROM TABLE CAPE, TASMANIA. 503 



Age-relations of Cycloloculina and Sherbornina. — Messrs. Heron-Allen 

 and Earland obtained their specimens of Cycloloculina from amongst derived 

 fossils from Tertiary strata at Selsey. The majority of the fossils found there 

 are, however, of Middle Eocene age, so that the greater chances point to 

 that rock-series as their source of origin. The present Miocene Sherbornina 

 seems to be a distinct modification of Cycloloculina through the accession of 

 secondary shell-growth and the development of external chamberlets super- 

 imposed on the median series. 



Occurrence. — Moderately common. In the Crassatellites Bed of Wynyardi, 

 Table Cape, Tasmania. 



Age. — Miocene or Janjukian. 



EXPLANATION OF PLATE 32. 



Fig. 1. Sherbornina atkinsoni, gen. et sp. nov. Ilolotype. Miocene (Janjukian). Table 

 Cape, Tasmania. External surface of test showing annulate plan of growth over- 

 lain witli tegulous layer of secondary chamberlets. X 21. 



Fig. 2. S. atkinsoni. Horizontal section through median plane, showing the discorhine 

 stage passing into the annulate series. The widely-spaced partitions of the annu- 

 late series of chamberlets are seen near the centre and also towards the periphery. 

 The tegulate or overlapping chamberlets of the secondary or external layer are seen 

 halfway to the centre of the test. X 24. 



Fig. 3. S. atkinsoni. Vertical median section through test, showing the relation of the 

 median to the external series of chamberlets. X 34. 



Fig. 4. S. atkinsoni. Structural sketch drawn from micro-section, m., loculi of median 

 series connected by coarse tubules ; ex., loculi of external series. X 68. 



Fig. 5. S. atkinsoni. Structural sketch drawn from micro-section. m., loculi of median 

 series; ex., loculi of external series ; s., septa of median series: t., shell-wall between 

 median and outer chamberlets, showing coarse perforations. X 72. 



