1872.] JONES AND PAEKEE— CEETACEO'US FOEAMINIEEEA. 121 



fails to present some variety or siibvariety of Pulv. re^ancla. Of 

 the Pidv.-Menardii group there are representatives in Nos. 1, 4 

 5, 6, 7, 9, 10, 12, 13, 15, 16, 19, and 20. Of the elerjans group 

 there are abundant and strongly marked forms in relatively few- 

 strata ; and all but one of them are very close to, indeed scarcely 

 separable from, the typical elegans, except by the comparative 

 richness of the shell-growth. Columns 1, 2, 3, 8, 11, and 18 (?) 

 have Pulv. elegans or some of its subvarieties ; and its greatest abun- 

 dance is decidedly with the Lower Cretaceous rocks. A very few 

 Pulvhmlinct} of the ScJireibersii group are scattered here and there 

 through the series — columns 4, 8, and 17. 



Rotalia is represented by one variety of 11. Beccaril, namely B. 

 exsculpta, in columns 8 and 16, and far more persistently by the deep- 

 sea variety B. nmhilicata in Nos. 2, 8, 9, 10, 11, 12, 13, and 19. 



AH these typical species, and several of their varietal forms, have 

 continued through the Tertiary period on to our oAvn times, and are 

 to be found in some existing sea or ocean. The chief distinction 

 between the Cretaceous Rotalines and those of the present day is, 

 that a vast number of varietal forms, which have sprung ujd during 

 the intervening ages, indicate, by their multiplicity, the varjdng 

 conditions of successive and changing marine areas, with differing 

 limits, depths, and climates. 



This is showii in Table II. (p. 123), by which we follow, though 

 with unequal steps, the progressive development of the several types, 

 as far as the materials before us will serve. 



Thus the " conical" Plcmorhulincp began early ; they are present 

 in the Lower Cretaceous deposits; they abound in the White Chalk, 

 the Tertiary beds, and the Atlantic. PI. Ungeriana is the most per- 

 sistent form. The " nautiloid " or Anomaline Planorbidince abound 

 in both the Lower and the Upper Cretaceous formations, and in the 

 Tertiaries ; but they are not so predominating in the Atlantic. PI. 

 ammonoides is the leading and lasting form. On the other hand, the 

 " plano-convex" orTruncatuline P?rt;io?"6i{Zm(:t;have flourished freely 

 throughout and nearly everywhere, in some subvariety or other of 

 Truncatulina lohatida. The orbicular, concentric, plano-convex PI. 

 mediterranensis (vidgaris) is a later form ; and its annular growth 

 indicates a morphological position higher than that of its simply 

 coiled allies. 



Pidvinidina repanda (proper) is represented in the Chalk of 

 Maestricht, but in none of the other Cretaceous beds. It is rare in 

 the Tertiaries of our Table (occurring only in the Pliocene), but is 

 scattered throughout the Atlantic. P. auricula existed in the Num- 

 mulitic sea, abounded in the mid-Tertiary times, and, living now, is 

 abundant in some places ; but it is wanting in the Chalk. P. Me- 

 nardii, however, was one of the early representatives of the genus. 

 In New Jersey (Forth America) it occurs in the Greeusand. With 

 us it begins with the White Chalk, and has continued with increased 

 prolificness till now. P. Sc7i7-eibersii occurs sporadically in the Green- 

 sand of New Jersey, the Chalk-formations of Eastern Europe, the 



