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Tuatara: Volume 8, Issue 1, October 1959

Figs. 21-26. Various arrangements of chaetae; diagrammatic representations of chaetal arrangements as seen in a cross-section of the body. — Fig. 21: Ten chaetae per segment: this arrangement is known only in the two species of Decachaetus. Fig. 22: Twelve chaetae per segment, arranged in pairs. — Fig. 23: Twelve chaetae per segment, fairly evenly spaced on each side of the body. Fig. 24: Twelve chaetae per segment, a ventro-lateral pair and a dorso-lateral group of four closely spaced chaetae …

Figs. 21-26. Various arrangements of chaetae; diagrammatic representations of chaetal arrangements as seen in a cross-section of the body. Fig. 21: Ten chaetae per segment: this arrangement is known only in the two species of Decachaetus. Fig. 22: Twelve chaetae per segment, arranged in pairs. Fig. 23: Twelve chaetae per segment, fairly evenly spaced on each side of the body. Fig. 24: Twelve chaetae per segment, a ventro-lateral pair and a dorso-lateral group of four closely spaced chaetae on each side of the body; this arrangement is known only in Diporochaeta caswelli. Fig. 25: More than twelve chaetae per segment, fairly evenly spaced on each side of the body. Fig. 26: More than twelve chaetae per segment, arranged in pairs. Figs. 27, 28. Diagrams showing the lines of chaetae, to which various pores and structures are referred. Figs. 29-38. Various arrangements of male and prostatic pores and associated structures in megascolecid earthworms. Figs. 29, 30: Two pairs of prostatic pores, on IT and 19, in line with chaeta f, each pore on a prominent conical papilla; longitudinal seminal groove joins the two prostatic pores on each side, curving slightly laterally and passing between chaetae f and g on 18. Male pores in seminal grooves on 18, between chaetae f and g. The species illustrated is Hoplochaetina polycystis. Figs. 31, 32: Two pairs of prostatic pores, on 17 and 19. in line with chaeta a, each pore on a prominent rounded papilla; a broad longitudinal ridge joins the two prostatic papillae of each side, curving slightly laterally across 18, and passing between chaetae a and b. Seminal grooves run along the ridges, and male pores-are in these grooves, on 18, between chaetae a and b. The species illustrated is Octochaetus sylvestris. Fig. 33: Two pairs of prostatic pores, on 17 and 19, in line with chaeta a, each pore in the centre of a small pale area, not on a papilla. Seminal grooves running longitudinally across 18, close to chaeta a; male pores in seminal grooves on 18, beside chaeta a. The species illustrated is Maoridrilus gravus. Figs. 34, 35: Two pairs of prostatic pores, on 17 and 19, each pore on an elongate, nipple-shaped papilla, the two papillae of each side overhanging 18. A prominent longitudinal ridge joins the two papillae of each side, curving slightly laterally across 18, and seminal grooves follow the crest of the ridge; male pores are on 18, one on each side, in the seminal grooves. The species illustrated is Deinodrilus kanieriensis; in this species the prostatic papillae are exceptionally elongated. Figs. 36, 37: One pair of prostatic pores, on 17, each pore on a small rounded papilla, slightly medial to line of chaeta b. Short seminal groove runs back down each papilla from the prostatic pore to the anterior edge of 18; male pores on 18, one on each side, close to anterior margin, at end of seminal grooves. The species illustrated is Rhododrilus agathis. Fig. 38: One pair of prostatic pores, on 17, occupying the position of the pairs of chaetae a b; pores not on papillae. Seminal grooves running back to the anterior edge of 18; male pores ac end of seminal grooves. The prostatic pores, seminal grooves and male pores are all located in a median ventral depression extending across 17 and overlapping slightly on to 16 and 18. The species illustrated is Neochaeta forsteri.

Figs. 21-26. Various arrangements of chaetae; diagrammatic representations of chaetal arrangements as seen in a cross-section of the body.
Fig. 21: Ten chaetae per segment: this arrangement is known only in the two species of Decachaetus. Fig. 22: Twelve chaetae per segment, arranged in pairs.
Fig. 23: Twelve chaetae per segment, fairly evenly spaced on each side of the body. Fig. 24: Twelve chaetae per segment, a ventro-lateral pair and a dorso-lateral group of four closely spaced chaetae on each side of the body; this arrangement is known only in Diporochaeta caswelli. Fig. 25: More than twelve chaetae per segment, fairly evenly spaced on each side of the body.
Fig. 26: More than twelve chaetae per segment, arranged in pairs.
Figs. 27, 28. Diagrams showing the lines of chaetae, to which various pores and structures are referred.
Figs. 29-38. Various arrangements of male and prostatic pores and associated structures in megascolecid earthworms.
Figs. 29, 30: Two pairs of prostatic pores, on IT and 19, in line with chaeta f, each pore on a prominent conical papilla; longitudinal seminal groove joins the two prostatic pores on each side, curving slightly laterally and passing between chaetae f and g on 18. Male pores in seminal grooves on 18, between chaetae f and g. The species illustrated is Hoplochaetina polycystis. Figs. 31, 32: Two pairs of prostatic pores, on 17 and 19. in line with chaeta a, each pore on a prominent rounded papilla; a broad longitudinal ridge joins the two prostatic papillae of each side, curving slightly laterally across 18, and passing between chaetae a and b. Seminal grooves run along the ridges, and male pores-are in these grooves, on 18, between chaetae a and b. The species illustrated is Octochaetus sylvestris. Fig. 33: Two pairs of prostatic pores, on 17 and 19, in line with chaeta a, each pore in the centre of a small pale area, not on a papilla. Seminal grooves running longitudinally across 18, close to chaeta a; male pores in seminal grooves on 18, beside chaeta a. The species illustrated is Maoridrilus gravus. Figs. 34, 35: Two pairs of prostatic pores, on 17 and 19, each pore on an elongate, nipple-shaped papilla, the two papillae of each side overhanging 18. A prominent longitudinal ridge joins the two papillae of each side, curving slightly laterally across 18, and seminal grooves follow the crest of the ridge; male pores are on 18, one on each side, in the seminal grooves. The species illustrated is Deinodrilus kanieriensis; in this species the prostatic papillae are exceptionally elongated. Figs. 36, 37: One pair of prostatic pores, on 17, each pore on a small rounded papilla, slightly medial to line of chaeta b. Short seminal groove runs back down each papilla from the prostatic pore to the anterior edge of 18; male pores on 18, one on each side, close to anterior margin, at end of seminal grooves. The species illustrated is Rhododrilus agathis. Fig. 38: One pair of prostatic pores, on 17, occupying the position of the pairs of chaetae a b; pores not on papillae. Seminal grooves running back to the anterior edge of 18; male pores ac end of seminal grooves. The prostatic pores, seminal grooves and male pores are all located in a median ventral depression extending across 17 and overlapping slightly on to 16 and 18. The species illustrated is Neochaeta forsteri.