230 DR. CARPENTER'S RESEARCHES ON THE FORAMIN1FERA. 



enabled to forward from time to time, regarding those other typical forms of Fora- 

 minifera of which I have made a special study, it is not my intention to do more 

 than state the results ; hoping that they may be understood to have been attained by a 

 method of inquiry as closely resembling that which I have here followed through its 

 details, as the circumstances of each case may have admitted. I would have it borne 

 in mind throughout, that, as has been admirably remarked by one of the most accom- 

 plished Botanists of our time, " the Naturalist who has the true interest of science at 

 heart, not only feels that the thrusting of an uncalled-for synonym into the nomen- 

 clature of science is an exposure of his own ignorance, and deserves censure, but that 

 a wider range of knowledge and a greater depth of study are required, to prove those 

 dissimilar forms to be identical, which any superficial observer can separate by words 

 and a name" (Dr. J. D. HOOKER, op. cit. p. 14, note). 



EXPLANATION OF THE PLATES. 



PLATE IV. 



Structure of the Animal of Orbitolite. 



Fig. 1. Entire Animal, from a small and simple disk, the shell having been removed 

 by maceration in acid ; in the peripheral portion the segments of sarcode 

 are wanting, and the structureless residuum of the shell is alone seen : 

 magnified 40 diameters. 



Fig. 2. Appearance of a portion of Sarcode, highly magnified : 180 diam. 



Fig. 3. Portion of the body of one of the more complex forms (resembling fig. 4), in 

 which the sarcode has broken up into little spheres (gemmules?); a, a, 

 superficial segments ; b, b, annular band : 180 diam. 



Fig. 4. Portion of the body of one of the more complex forms, as seen in vertical 

 section ; aa, a'a', upper and lower rows of superficial cells, each cell con- 

 nected, at its two extremities, with the annular bands bb and b'b' of two 

 zones ; from these annular bands spring the columnar segments cc, cV, 

 those of the same zone occasionally passing into each other, and commu- 

 nicating with those of the next zone by oblique peduncles alternately pass- 

 ing towards one side and the other: 150 diam. (N.B. This figure is 

 somewhat ideal, being made-up from several preparations ; but for every 

 point which it represents, these preparations give warranty.) 



Fig. 5. Nucleus and first two annular zones, exhibiting the typical conformation ; 

 a, the central segment ; bb, the circumambient segment, from the entire 

 margin of which are given off peduncles of sarcode, which give origin to 

 the first annular zone : 84 diam. 



