This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1892 Excerpt: ...in its transverse view. X. Tetkacentrotum, Wolle. Plate XXV, figs. 8. 9. About as long as broad, smooth, constriction deep, sinus enlarged outwardly; semi-cellssubreniform or subhexagonal. base somewhat convex, ends broadly rounded; basal angles on each side armed with a pair of subulate spines; central protuberance ...
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This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1892 Excerpt: ...in its transverse view. X. Tetkacentrotum, Wolle. Plate XXV, figs. 8. 9. About as long as broad, smooth, constriction deep, sinus enlarged outwardly; semi-cellssubreniform or subhexagonal. base somewhat convex, ends broadly rounded; basal angles on each side armed with a pair of subulate spines; central protuberance low, over it sometimes a series of bead-like granules. Diameter 33-37 //., without spines; 60 //. with spines. Pond, Sussex Co., N..1. The form and character of this species is very near C. andlopazum, but it is smaller and bears only two pairs of aculei, not four or six. Genus, AETHEODESMUS, Ehrb. Cells simple, compressed, deeply constricted in the middle; semi-cells broader than long, with a single spine or mucro on each side, but otherwise smooth and entire. A. Convergen'3, (Ehrb.), Ealfs. Plate XXVI, figs. 19, 20, 21. Semi-cells elliptic, each having its spines curved towards those of the other semi-cell. Diameter 38-40 M-Several varieties are acknowledged to this species, one with shorter and almost straight spines, another with broadly fusiform cells. Plate XXVI, figs. 22, 23,1 place with the varieties. This species is common. A. Fragilis, Wolle. Plate XXVI, figs. 16, 17, 18. Semi-cells broad, oblong-oval; aculei straight and parallel, . e., the aculeus of one semi-cell is parallel with that of the other; deciduous. Chlorophyllous nuclei, two. Diameter 33-38 //.; length somewhat less. Central New Jersey, pond at Hammonton, and other waters. A. Eauii, Wolle. Plate XXVI, figs. 13, 14, 15. Cells slightly longer than broad, aculeated or verrucose; aculei short and stout, deciduous, leaving, after falling off, large verrucae; usually six on the margin of each end, and two curved series of about six each on the membrane within margin; semi-cell b...
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