. The Annals and magazine of natural history; zoology, botany, and geology. Natural history; Zoology; Botany; Geology. two Specimens of Rhynchopora Geinitziana. 125 Neither specimen exhibits any portions of an impression of the inner surface of the valves. 1. The specimen with the umbone of the large valve broken off.— The outer or original surface of this specimen seems to have disappeared, while in some places it is obscured with foreign matter. In the former condition, the remaining test displays numerous black dots*. In a few places the specimen has been a little filed or cut down. The tes
. The Annals and magazine of natural history; zoology, botany, and geology. Natural history; Zoology; Botany; Geology. two Specimens of Rhynchopora Geinitziana. 125 Neither specimen exhibits any portions of an impression of the inner surface of the valves. 1. The specimen with the umbone of the large valve broken off.— The outer or original surface of this specimen seems to have disappeared, while in some places it is obscured with foreign matter. In the former condition, the remaining test displays numerous black dots*. In a few places the specimen has been a little filed or cut down. The test that remains is, in several places, of considerable thickness, which is well exhibited on the fractured portion, where the umbone is broken off". At this part the black dots are seen (as represented in the surface-figure and longitudinal section, figs. 1 and 2) not only on the surfaces a and c, but also on the intermediate por- tion b. A broken part on the small valve, between the umbone and the an- tenor margin, also shows the test to be of considerable thickness ; and in certain a lights some of the black dots appeared as if they formed the terminations of fine hair-like lines passing down through its Yis. 2. thickness. In no instance could I con- o, vince myself that they were " mere acci- q l\ I dental results of infiltration," as main- \ y" ') tained by Dr. Carpenter in one of his ^^ ' letters to me: their regularity completely forbids the idea. Black dots are nearly everywhere exhibited on the abraded surface of this valve: the exceptional cases will be noticed here- after. The observations stated completely prove, in my opinion, that the black dots are not simply " pits upon the internal surface of the shell;" or they ought not to be seen on the surface of every layer of tissue exposed : the whole of the layers, be it understood, form a series of considerable thickness. On the contrary, seen under the circumstances named, they canno
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