Renews — Daivsorts Baton of Life. 171 



the magnesian silicates of the Eozoon are analogous to the glauconite 

 of other infiltrated organisms is denied by some ; but, whether an 

 infiltration into empty cavities, or a replacement of animal matter, or 

 an altered mud or ooze, already pressed into chambers and tubes, it 

 still appears to be analogous to the not very different glauconitic ^ 

 infillings of pores and holloMrs in Echinodermatal, Coralline, Fora- 

 miniferal, and Polyzoan tissues, and even of minute Molluscan shells, 

 as known in both recent and fossil specimens. 



Other objections have been made to the supposed Foraminiferal 

 structure itself, particularly to the asserted presence of the primary, 

 tubuliferous, '' nummuline " layer, or ''proper wall" of the test 

 on both the upper and the lower surface of each successive segment 

 of sarcode, such as is exhibited in Dr. Dawson's diagram, pi. 4, 

 p. 58, and in the drawings at p. 176. Traces, however, of such an 

 enveloping primary layer, on the lower face of the segments, lying 

 on the preceding whorl of a discoid Foraminifer (as well as on the 

 upper or outer surface, and on the front and back, where it makes 

 the septa), is visible in both Dr. Carpenter's and Mr. Carter's hori- 

 zontal section of Operculina arabica, cut a little out of the median 

 plane.^ 



Dr. Dawson takes care to show that Eozoon is not without its 

 Khizopodal allies, and even associates. He finds in the Laurentian 

 limestones numerous isolated little bodies (Ai'chcBosplKerince) , either 

 single, beaded, or heaped (like Glohigerina), which he regards as 

 having been simple Foraminifera with tubulated walls (figs. 18 and 

 34, pp. 67 and 138), but whether immature forms of Eozoon, or 

 quite distinct, he does not decide. He especially dwells on the 

 existence of old Cambrian and Silurian Ehizopods, of large size, 

 such as the ArcTiceocyathus, Stromatopora, Cannopora, Cosnostroma, 

 and Beceptaculites. Of the last. Dr. C. Gumbel,^ in 1875, published 

 full particulars as to its Foraminiferal characters ; Grustav Lindstrom ^ 

 had already, in 1870, referred Coenostroma discoideum (Lonsdale) to 

 the Ehizopods; and Dr. Carpenter in 1867 (''Siluria," new ed. 

 p. 547) expressed a decided opinion on the Ehizopodal structure of 

 Stromatojpora striatella. These points are not stated, however, by Dr. 

 Dawson. That other Pala30zoic Foraminifera occur, we well know. 

 H. B. Brady's lately discovered Arclicediscus, from the Carboniferous 

 Limestone, referred to in a note at p. 164, is a Nummuline Forami- 

 nifer, of irregular growth, and to some extent represents an inter- 

 mediate form between Eozoon and Nummidina. Indeed the last- 

 mentioned, and its allies, Fusidina and Amphistegina, have also been 

 found in the Carboniferous rocks, with many other Foraminifera, 

 about to be described by Mr. H. B. Brady, F.E.S. The presence, 

 therefore, of Foraminifera in the older rocks is not a matter of 

 surprise, and the relatively large size of the individuals is no longer 

 to be discredited, since Farherim as large as small cannon-balls have 



^ Hydrous alumino-maguesian silicates. 



2 Pliil. Trans. 1859, pi. 4, fig. 5 ; and Ann. Nat. Hist., ser. 2, vol. x. pi. 4, fig. 5 



3 Abhandl. K. bayer. Akad. Wiss. Clas. ii. vol. xii. 

 * K. Yet. Ak. Handl., vol. ix. No. 6, 1870. 



