Ecological animal geography; an authorized, Ecological animal geography; an authorized, rewritten edition based on Tiergeographie auf ockologischer grundlage ecologicalanimal00hess Year: 1937 THE PELAGIAL 227 only a small excess of weight in this manner and it is especially effec- tive only for small animals, which have an intrinsically high value of the surface-weight proportion. The simplest means of enlarging the ventral surface lies in the flattening of the body. Leptodiscus, the light- producing flagellate, most Hydromedusae and Scyphomedusae, the turbellarian Haplodiscus, the pelagic ne
Ecological animal geography; an authorized, Ecological animal geography; an authorized, rewritten edition based on Tiergeographie auf ockologischer grundlage ecologicalanimal00hess Year: 1937 THE PELAGIAL 227 only a small excess of weight in this manner and it is especially effec- tive only for small animals, which have an intrinsically high value of the surface-weight proportion. The simplest means of enlarging the ventral surface lies in the flattening of the body. Leptodiscus, the light- producing flagellate, most Hydromedusae and Scyphomedusae, the turbellarian Haplodiscus, the pelagic nemertines, the crustacean larva Fig. 51 Fig. 52 Fig. 51.—Hastigerina digitata, a pelagic foraminifer. After Rhumbler. Fig. 52.—Globigerina bulloides, a pelagic foraminifer. After Ziegler. Phyllosoma (Fig. 53d), the copepod Sapphirina, and many others are thus flattened. Lateral projections, which may be branched in addi- tion, often occur. Such apparatus is most developed among the radio- larians and Foraminifera, in which the long pseudopodia are supple- mented by spines of the test. Such 'suspensory bristles' are notable in Hastigerina (Fig. 51) and Globigerina (Fig. 52). This means of support is less developed among the Metazoa; some of the most conspicuous examples, including annelid worms, their larvae, mollusks, crustaceans, and a fish larva, are shown in Fig. 53. Young transformed starfishes and sea urchins (Fig. 54) have relatively long tentacles and
Size: 1523px × 1313px
Photo credit: © Bookworm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: archive, book, drawing, historical, history, illustration, image, page, picture, print, reference, vintage
