110 Messrs. VV. iv. Parker andT. R. Jones on the 



infillings of funnel -shaped holes or pores, the nature of these 

 granulations was misunderstood by MM. d'Archiac and Hainie. 

 In a Nummulite of any of the groups the septal lines exposed 

 on the surfaces may be thickened, built up, or exaggerated by 

 ridges or granules of hyaline shell-substance permeated with 

 tortuous passages— part of the so-called " vascular system " of 

 the shell ; and these exogenous granules need not be confined to 

 the septal lines, but may be planted in the interspaces, as in Am- 

 phistcgince and other cognate forms, and will thus stand as hues 

 and pillars of division to the alar lobes as the new segments are 

 successively added. This is markedly the case in N. scabra, 

 Lam., the granulated variety of N. lavigata, 2ind indeed in nu- 

 merous instances among Nummulince and their allies. In many 

 Nummulites the granulate surface may be found at one period 

 of growth, and the smooth at another; for, if a new segment or 

 segments have been lately added, the surface will be far smoother 

 than in the stage when the external increase of the septal lines 

 and pillars only is going on. 



The group No. 5, " plicatee vel striatre," contains a great many 

 varieties characterized by a simple radiate arrangement of the 

 alar lobes, which are usually elongate triangular, straight or 

 slightly curved, either falciform or sigmoid. These Nummulites 

 are usually small, and are well typified by Num. planulata, 

 Lamk. We should have preferred the term " radiatge " for this 

 group. 



No. 6 is the Assiline group (" explanatse")^ m which the whole 

 of the spire is apparent from the want of the alar lobes. Assi- 

 lina, however, like Operculina, ])asses by insensible gradations 

 into Nummulina, by the varying development of the lateral lobes 

 or flaps. 



There are individvial specimens that tend to show a linking 

 together of the " sinuate," " reticulate," and " radiate" groups ; 

 but for the present we propose to regard these as three specific 

 groups, headed respectively by Nummulina complanata, N. lavi- 

 gala, and N. planulata. The Assiline forms are probably related 

 as varieties to the "radiate" and "sinuate" groups. 



Having said thus much respecting the Nummulites generally, 

 we return to Fichtel and INIoll's illustrations, with the following 

 remarks : — 



N. Mamilla and A^. lenticuluris, var. a, do not present 

 any indication of the superficial lobes ; but, from the style of 

 their chambers, they probably belong to the "radiate" group, 

 and, for what we can see, arc of the same species, the relative 

 amount of convexity not being essentially distinctive. 



A', lenticultiris, vai-. /3, may be the N. Lucasann (of the " ra- 

 diate'' group), as stated by MM. d'Archiac and Haimc, but is 



