. Fresh-water biology. Freshwater biology. THE Leeches (hirudinea) 657 42 (39) No copulatory glands; penis filamentous; colors variable, dorsum usually green with six or four brown stripes, sometimes broken. European medicinal leech; introduced. Hirudo medicinalis Linnaeus 17 58,. Fig. 1004. Birudo medicinalis. External morphology from the dorsum. The numerals on the right indicate the annuli, those on the left the somites, the index lines running to the neural annuli; isl P. and J-/A P., first and last nephridiopores. Natural size. (After Whitman.) 43 (38) Jaws variable, sometimes rudimentary
. Fresh-water biology. Freshwater biology. THE Leeches (hirudinea) 657 42 (39) No copulatory glands; penis filamentous; colors variable, dorsum usually green with six or four brown stripes, sometimes broken. European medicinal leech; introduced. Hirudo medicinalis Linnaeus 17 58,. Fig. 1004. Birudo medicinalis. External morphology from the dorsum. The numerals on the right indicate the annuli, those on the left the somites, the index lines running to the neural annuli; isl P. and J-/A P., first and last nephridiopores. Natural size. (After Whitman.) 43 (38) Jaws variable, sometimes rudimentary or absent; teeth when present all or partly in double series; gastric ceca one large posterior pair only. Chiefly predaceous 44 44 (47) Jaws short and high; teeth small, only partly in two series; no penis; genital orifices separated by three or four rings, surrounded by systems of gland pores . Philobdella Verrill 1874. 45 45 (46) Denticles about 35; narrow median dorsal and broader marginal yellow stripes and a few brown spots. Philobdella gracile Moore 1901. Philobdela takes the place of ^ocro- bdella in the Gulf States and has singular habits. It is the native "blood-sucker " of that region. Fig. 1005. Philobdella gracile. A, external genital orifices (^ , 9) with their re- spective systems of gland pores (cgp $ and cgp 9 ); np, nephridiopores; sbm, vl, vm, submargmal, lateral, and median sensillae. X 3^. (After Moore.) B, outline of a jaw with teeth. X 35. (After Moore.) \&v 1 vl itJm ___,ââj '-L --Lisi-^ np___ â¢Jsn/ r- â M^^rr J' tfi :ri f» G 57 â ^^ Iâ xmj "K^mv \ \- \\^r<^'' ) cgp' "P 46 (45) Denticles about 20; no median dorsal stripe and no spots; two faint stripes of reddish brown separated by a narrow line of blackish on each side of dorsum. Philobdella floridana Verrill 1874. 47 (44) Jaws rather small and retractile into pits or absent; teeth when present coarse and all in double series; penis filamentous; genital orifices sep
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectfreshwa, bookyear1918
