1905. | the English Species of Nummulites, etc. 307 
are apparent, as may be gathered from Plate 5,aand a. In the Huntingbridge 
specimens the height of the chambers as seen in section (measured along the 
radius of the test) is less in proportion to their breadth than in those from 
Alum Bay. Moreover the backward slope of the septa is less marked in the 
Huntingbridge specimens. In both these respects it happens that these latter 
vary in the direction of WV. variolarvus. However, in the flatness of the test 
(cf. a’ and a’) and in the large size of the megalospheres (fig. 1) there is no 
approach whatever to variolarius. In his “ Ktude” (p. 170) de la Harpe says 
of the species under consideration :— . 
“Les cloisons et les chambres sont irreguliéres dans leur forme, leur nombre, 
leur épaisseur et leur inclinaison.” 
I have no reason to doubt, therefore, that Professor Jones was justified (11) 
in referring the Huntingbridge specimens to WV. wemmelensis var. elegans, w.2., 
to WV. Orbignyt var. elegans. 
Among 44 specimens examined in section (fig. 1) 40 are megalospheric and 
4 microspheric, but this proportion is not a true indication of their relative 
eo 
NUMMULITES VARIOLARIUS e 
(Whrtectttf Bay) ® @ 
2 oe? e 
® 8680 © 
e 0090806 
© ©3808G000? 
e €60060003 
2@00 933963008 
@860 2003000069 
J @ 200000669 85800% 98 
e e @ €0009909°9908668600 
e t) @Ge0Cecsoreogoeer 990 063929939 
ee e@ O80 00 0093 0000 000 06908908 O08090 e 
O ° © 
N. ORBIGNY! var. ELEGANS 4 it Las 
(Alum Bay) 09 €® 0070 e28 @ 
e 00090 ©€8 ©9090 €0 e@ co 
© 802609 5 80890 68 Cese0 
ee @ 0000009 69600960060 66090000 C00 c) 
Gare, . 
e > (TKR SRRPTSSSBS LASS SASSSESERRESBVIT SS 
es PTS Hie A a ee SRP A eka a ee ATA ENN ia Mh Lite Reka Pu Rie bio 
ee see Has SS Reger BS ests SS 8 Se ea s 8 es 
N.ORBIGNY?! var ELEGANS 
e 
(Hunting bridge ) ° 
e .-) 
o e 
e eo 0? ee 60 
ee © ce oe 089 0000 02600000 © 90 ° 
Fie. 1. Diagram showing the diameters of the Initial Chambers of the specimens 
measured, belonging to the species Vummulites variolarius and WV. Orbignyi var. 
elegans. 
Each specimen is represented by a dot. The size of each chamber (z.e., the mean 
between its long and short diameters, as seen in the section) is indicated by the 
horizontal distance of the dot from zero, on the left, and may be measured by 
reference to the scale, indicating 1/1000th of a millimetre (y’s). The dots for 
chambers of the same size are piled one above another. 
It will be seen that in respect of size the initial chambers of the species (or local form) 
fall, in each case, into two groups, the microspheric and megalospherie. 
