Manchester Memoirs, J W. Ixii. (,1917) 139 



This handsome species is not uncommon in my collections 

 and both the megalospheric and the microspheric forms have 

 been found. The latter however is much rarer than the former. 



338. Nu.MMUI.ITK5 (ASSILINA) MAMMILATA, (d ' ArclliaC.) 



338A. NUMMUUTES (Assilina) exponens, Sowerby. 



Numm. (Assil.) mammilato, d'Archiac, 1853, Descr., AjMm., 



groupe Nummulitique [nde, vol. 1, p. 154, pi. XI, figs. 6-8 

 Nummulina mammilata, d'Archiac. [847, Bull. Soc. G60I., 



France [2], vol. IV, p. loto. « 



Nit in miliaria exponens, Sowerby, [834, (1840.) Trans. Geol. 



Soc. London, [2], vol. V, p. ;io. pi, I \1, fiV i.|. 

 Numm. exponens, D'Archiac & rlaime, 1853, Descr. Ajiim. 



groupe Nummulitique Inde, vol. I, p. L48, pi. \, figs. 1 to. 



N. mammilata which is the megalospheric form is \er\ 

 much more common than N. exponens the microspheric form. 

 Of about twenty-five specimens examined only one was found 

 with a microsphere. This specimen differs somewhat from I In- 

 type in that the spire is rather more open than usual and the 

 chambers are broader. 



SUB-FAMILY CYCLOCLYPEIN E 



Genus Orbitoides, d'Orbigny 

 339. Orbitoides papyuacka, (Boubce.) 



Nummtilites papyracea, Boubee, 1832, Bull, Soc. (ieol. France, 



vol. II, p. 445, no figure. 

 Orbitoides (Discocycllua) papyracea, Giimbel, [868 (1X70). 



Abh. m.-ph. CI. k.-bayer, Ak. Wiss. vol. X, p. 690, pi. Ill, 



figs. 3-12, figs. 19-29. 



Very common, particularly in the hard layers of the lower 

 part of the Marls where seams several inches thick occur, 

 formed almost entirely of this species with an admixture of 

 different species of Nummulites. In the softer beds of the Marl 

 it is rarer, but still the commoner form of the genus 



340. Orbitoides (Discocyclina) aspera, Giimbel. 



Orbitoides {Discocyclina) aspera, Giimbel, 1868 (1870), Abh. m. 



ph. CI. K. bayer, Ak. Wiss, vol. X, p. 698, pi. Ill, figs. 



13-14; and figs. 32-34. 



Rare in upper soft Marls, more frequent in lower and 

 harder beds. 



