. Fresh-water biology. Freshwater biology. AQUATIC EARTHWORMS 641 36 (27). Sperm-ducts without definite prostate glands and opening into a common median chamber with single ventral median open- ing on XI; spermathecal pores on X; setae of dorsal bundles aU cleft Rhizodrilus Frank Smith 1900. One species thus far known in North America, R. lacleus Frank Smith, found in roots of Sagittaria in Illinois. Has two kinds of genital setae on IX and XI; length 75-100 mm.; whitish in appearance (Smith, 1900). Michaelsen includes this species in Monopylephorus Levinsen. Fig. 989. Rhizodrilus lacteus. a,
. Fresh-water biology. Freshwater biology. AQUATIC EARTHWORMS 641 36 (27). Sperm-ducts without definite prostate glands and opening into a common median chamber with single ventral median open- ing on XI; spermathecal pores on X; setae of dorsal bundles aU cleft Rhizodrilus Frank Smith 1900. One species thus far known in North America, R. lacleus Frank Smith, found in roots of Sagittaria in Illinois. Has two kinds of genital setae on IX and XI; length 75-100 mm.; whitish in appearance (Smith, 1900). Michaelsen includes this species in Monopylephorus Levinsen. Fig. 989. Rhizodrilus lacteus. a, ordinary uncinate seta; b and c, genital setae from DC and XI. X ISO. (After Smith.) 27 (26) Sperm-ducts with definite prostate glands 28 28 (29) Ten or more small definite prostates on each sperm-duct; no capil- hform setae; setae indistinctly cleft and sometimes simple- pointed Telmatodrilus Eisen 1879. Two species, T. vejdovskyi Eisen and T. mcgregori Eisen, are found in California. 29 (28) Sperm-ducts each with one definite prostate gland (Fig. 990). 30 30 (31) Dorsal setae all uncinate and similar to ventral setae; penis with chitinous sheath Limnodrilus Claparede 1862. Several species have been described from California (Eisen, 1885). L. gracilis Moore has recently been described from Lake Erie (Moore, 1906). In L. dapare- dianus Ratzel, an abundant species of wide distribution, the length of the chitinous penis sheath is 8-30 times its diameter. Fig. 990. Reproductive organs of Limnodrilus gracilis, t, spermary; sp, spermatheca; /, spermi- ducal funnel; u, u, sperm-duct; *, prostate gland; r, atrium; at, penis and penis sheath; ov, ovary. X 20. (After Moore.). 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 Ward, Henry Baldwin, 1865-1945; Whipple, George Chandler, 1866-1924. joint author. New York, Jo
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectfreshwa, bookyear1918
