. Fresh-water biology. Freshwater biology. ^40 FRESH-WATER BIOLOGY 29 (28) With two very small eyes, yellowish by transmitted light, whitish by reflected light, lying just before the brain in the widest re- gion of the pharynx. Prorhynchus applanatus Kennel 1888. Length 4 mm. White. Bod> much flattened at both ends. Pharynx very muscular. In- testine a slender straight tube with one diverticulum extend- ing anteriorly under the phar- ynx and numerous slender very closely set lateral diverticula. Greenhouse, University of Ne- braska, Lincoln, if-^A ' '^sqi^'^ Prorhynchus a
. Fresh-water biology. Freshwater biology. ^40 FRESH-WATER BIOLOGY 29 (28) With two very small eyes, yellowish by transmitted light, whitish by reflected light, lying just before the brain in the widest re- gion of the pharynx. Prorhynchus applanatus Kennel 1888. Length 4 mm. White. Bod> much flattened at both ends. Pharynx very muscular. In- testine a slender straight tube with one diverticulum extend- ing anteriorly under the phar- ynx and numerous slender very closely set lateral diverticula. Greenhouse, University of Ne- braska, Lincoln, if-^A ' '^sqi^'^ Prorhynchus applanatus. From life. X 20. (After Kennel.) 30 (3) Female sexual organs divided into ovary and yolk glands. Male sex organs complex Section Lecithophora . 31 Ovary in general small and simple. Yolk glands extremely variable, elongated, lobed, or forming a network which anastomoses. Chitinous portion of male copulatory organ very complicated and variable in form. 31 (74) Proboscis either lacking entirely or if present without a definite sheath Subsection Lipoehynchia . 32 This division contains the greater part of the fresh-water Turbellaria. 32 (61) With a cask-shaped pharynx parallel to the ventral surface or shghtly inclined and with the end directed forward. But one genital pore Family Dalyellidae . 33 With the exception of the genus Opistomum, which is not represented in this country, the pharynx is typically cask-shaped and opens into the anterior end of the intestine. The genital pore opens on the ventral surface posterior to the mouth. Ovary simple. Yolk glands variable, female receptaculum seminis and a simple uterus are present. Testes always paired. Chitinous portion of male copulatory organ often very complex. Pigment eyes usually present, but without other sense organs. Protonephridium consists of two principal branches which open on the ventral surface. Rhabdoids and glands of integument prominent. SS (60) Without a separate pocket for the chitinous part of the cir
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectfreshwa, bookyear1918
