Annals of the South African Museum = Annale van die Suid-Afrikaanse Museum . drocladia, those of primary and secondary hydrocladia do notface one another. Hydrocladia generally heteromerous with alternating athecate and thecateinternodes, but many variations; the athecate internodes may be absent orduplicated, long or short, and may or may not bear a median internodes usually with one median inferior and one median superiornematotheca, but the nematotheca is often missing leaving only a naked sarco-phore, and this is especially common in the first thecate internode of the h
Annals of the South African Museum = Annale van die Suid-Afrikaanse Museum . drocladia, those of primary and secondary hydrocladia do notface one another. Hydrocladia generally heteromerous with alternating athecate and thecateinternodes, but many variations; the athecate internodes may be absent orduplicated, long or short, and may or may not bear a median internodes usually with one median inferior and one median superiornematotheca, but the nematotheca is often missing leaving only a naked sarco-phore, and this is especially common in the first thecate internode of the hydro-cladium. Nematothecae, when present, curved and scoop-shaped. Mediansuperior nematotheca situated behind distal part of adcauline thecal wallwhich is not completely adnate. Hydrotheca wider than deep, with more or less straight abcauline walland margin at least slightly oblique. Measurements (mm) Thecate internode, length .. .. 0,42-0,96 Hydrotheca, depth abcauline .. .. .. .. .. 0,12-0,19 diameter at margin 0,17-0,22 HYDROIDS FROM THE KERGUELEN AND CROZET SHELVES 41. Fig. 12. Oswaldella bifurca (Hartlaub). A-B. Normal parts of hydrocladia. C. Proximal end of hydrocladium showing origin from stem and first thecate internode which is without a nematotheca. Plumularia insignis Allman. D. Part of stem in thinner region showing origins of two branches and their preceding hydrocladia. E. Gonothecae. F. Part of hydrocladium. Scale in mm/10. 42 ANNALS OF THE SOUTH AFRICAN MUSEUM Remarks This material is assigned to O. bifurca with some hesitance, the decisionbeing based mainly on the shape of the hydrotheca, which is wider than deep,and on the method of branching. As regards the latter feature Tottons words(1930) are pertinent, when he says for O. bifurca Hydrothecae of hydrocladeand branch not strictly opposed, but facing slightly upwards. On the otherhand the features used by Totton as diagnostic for O. bifurca, namely once-branched hydrocladia and the absence of an inferior ne
Size: 1278px × 1955px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1800, bookdecade1890, booki, booksubjectnaturalhistory
