. Fresh-water biology. Freshwater biology. just back of tip, also at junction of head with cephalic appendages. Wider just in front of appendages than at any point posterior to them except in large specimens which are of about same width through pharyngeal region. Mature specimens much broader proportionally than immature. Asexual reproduction the usual method of propagation in most localities. Very restless and active. Collected from small ponds and spring-fed brooks either among algae or on sandy bottom and often where water flows swiftly. Neb., Mo., S. Dak., Wis., and Cal. Fig. 632. Planari
. Fresh-water biology. Freshwater biology. just back of tip, also at junction of head with cephalic appendages. Wider just in front of appendages than at any point posterior to them except in large specimens which are of about same width through pharyngeal region. Mature specimens much broader proportionally than immature. Asexual reproduction the usual method of propagation in most localities. Very restless and active. Collected from small ponds and spring-fed brooks either among algae or on sandy bottom and often where water flows swiftly. Neb., Mo., S. Dak., Wis., and Cal. Fig. 632. Planaria agilis. (A) Immature specimen from life. X8. {B) Sexual organs, dorsal view: m, uterus: m^ uterus tube; 0, oviduct; gp, genital pore; a, atrium; sv, seminal vesicle; vd, vas deferens: pi, cirrus lumen; la, limit of atrium. Much en- larged. (After Stringer.) 93 (92) Angle of head about 45°. Color reddish to yellowish-brown. Planaria dorotocephala Woodworth 1897. Length of immature specimens 13 mm. Head about one-sixth of total length of body. Uni- formly colored. Posterior margins of auricular appendages free from pigment. Sometimes a narrow Ught median streak. Pigment in spots or patches, not a network or evenly distributed as in P. agilis; ventral side much lighter than dorsal. Eyes just anterior to plane joining auricles. Intestine usually with accessory posterior intestinal trunks which arise either at the root of the pharynx like the two normal posterior trunks or exist as parallel branches of the latter. Those of a side usually unite with each other near their posterior terminations. Very active and restless. Sexual organs have not been described. III., Fig. 633. Planaria dorotocephala from life. X 7. (After Woodworth.) 94 (85) Anterior end clearly not pointed 95 95 (100) Anterior end truncated , 96 96 (99) Margin of anterior end with a median anterior and two lateral rounded projections giving a sinuous outline 97. Please note that these images are extracted fro
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectfreshwa, bookyear1918
