. The Annals and magazine of natural history; zoology, botany, and geology. Natural history; Zoology; Botany; Geology. 318 Mr. J. Ilopkinsoii on a Sjyecimen of the hydrotJiccfe, and thus have caused the polypaiy to be un- evenly compressed. The most perfect are pear-shaped in form, l-6th of an inch long, and at their narrow end, by which they are attached, about l-30th of an inch wide. They have appa- rently been bounded by a single marginal fibre, which is sli " " " ' " ? ' " " g,htly thickened at its edges, removed, has impressed a fine double groove on the surf
. The Annals and magazine of natural history; zoology, botany, and geology. Natural history; Zoology; Botany; Geology. 318 Mr. J. Ilopkinsoii on a Sjyecimen of the hydrotJiccfe, and thus have caused the polypaiy to be un- evenly compressed. The most perfect are pear-shaped in form, l-6th of an inch long, and at their narrow end, by which they are attached, about l-30th of an inch wide. They have appa- rently been bounded by a single marginal fibre, which is sli " " " ' " ? ' " " g,htly thickened at its edges, removed, has impressed a fine double groove on the surface of the shale. If the fibres were slender tubes, this appearance would naturally be presented; for their outer margins would offer the greatest resistance to compression. The so-called solid axis of the graptolite fre- quently presents a similar ap- pearance. At the proximal end of the polypary these fibres only are preserved, the oldest or first-formed gonotheca3 having fulfilled their function and pe- rished. The distal extremity of even the most perfect is not clearly defined, the impression of the capsule in most cases becoming gradually less per- ceptible from the proximal to the distal end. Sometimes the capsules are irregularly rup- tured, their torn jagged edges and, where the pyrites is Fiff. Diplograpsus prisfis witli reproductive capsules. Maijn. 3 diameters. being distinctly seen, while one has split along its marginal limit,along the line of the marginal fibre, which appears to have parted abruptly near the distal end of the capsule at one side, and S'plit acutely for some distance along the other side. This would appear to indicate that the capsule may be composed of two membranes joined together at their edges, through which the fibre, if it be not merely a tube formed by a kind of double marginal seam, has run. In no case can a distinct unruptured distal orifice be traced. The gonothecas present other peculiar appearances. To- wards their proximal end the
Size: 986px × 2535px
Photo credit: © Library Book Collection / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookce, booksubjectbotany, booksubjectgeology, booksubjectzoology
