. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. THE TWENTY-RAYED STARFISH. 211 which bears the anus. Ray IV. records 107 trials, ray III. 137, and ray II. 103 trials out of the total of 499; while rays V. and I. have only 74^/2 and 77j/2, respectively. This is, indeed, a very striking contrast to Ludwig's so-called " vorderer Interradius," , interradius , the ipso facto posterior end. If the physi- ological anterior rays of Pycnopodia arc in fact the morphological anterior rays, as represented by Ritter and Crocker (although theirs must be inverted), t
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. THE TWENTY-RAYED STARFISH. 211 which bears the anus. Ray IV. records 107 trials, ray III. 137, and ray II. 103 trials out of the total of 499; while rays V. and I. have only 74^/2 and 77j/2, respectively. This is, indeed, a very striking contrast to Ludwig's so-called " vorderer Interradius," , interradius , the ipso facto posterior end. If the physi- ological anterior rays of Pycnopodia arc in fact the morphological anterior rays, as represented by Ritter and Crocker (although theirs must be inverted), then all facts agree. (Compare Figs. 2, 3, and 7.) In Pycnopodia the line of bilateral symmetry lies along. B— FIG. S. Diagram to show the physiological anterior end of Asterias forbefi, and its relation to the madreporite. Line AAI plane of bilateral sym- metry ; BB, dissects the star into an anterior and posterior pole according to direction of locomotion. The number at the end of each ray indicates the exact number of attempts the star used that ray as " anterior " ray in locomo- tion ; ray e, is seen to have the largest number in its favor. (Ray 2 = III, Cuenot.) The sum of the trials indicates a " right " and " left " which cor- respond very well to a plan of bilateral symmetry. (From Cole.) the rays IV—A (ray A = VI.) ; this is explainable by the fact that five of the six primary rays become the anterior rays, with ray IV. in the lead, and rays III., II. on the left, and V., I. on the right (Fig. 7). The relation of the madreporite and of the anus to the clorso-radial muscles is then demonstrated (Figs. 2 and 3). Ray. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Marine Biological Laboratory (Woods Hole, Mass. ); Marine Biological Laboratory (Woods Hole, Mass. ). Annu
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Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
