DESCRIPTIONS OF GENERA AND SPECIES 537 



(8) Acanthodrilus hilgeri (MICHAELSEN). 

 Mandane Hilgeri, MICHAELSEN, SB. Hamb. wiss. Anst., vi, 1889, p. 8. 



Definition. Length, 95 mm.; diameter, 3 mm.; number of segments, 93. Colour, in alcohol, 

 grey violet above. Prostomium completely divides buecal segment. Clitellum, XIV-XVI, 

 complete. Setae strictly paired. Nephridiopores in front of dorsal setae. Male pores 

 corresponding to ventral pair of setae. Gizzard in segments VIII, IX, X. Spermathecal 

 pores in front of ventral pair of setae. No penial setae, the ordinary setae being present. 

 Sperm-sacs in IX-XL Spermathecae, with a single diverticulum longer than the pouch. 

 Ilab. -Corral, Chili. 



(9) Acanthodrilus pictus (MICHAELSEN). 

 Mandane picta, MICHAELSEN, loc. cit., p. 5. 



Definition. Length, 132 mm.; breadth (at ditellum), 8 mm.; number of segments, 135. 

 Segments not marked by annuli. Colour (in alcohol), brown ; after ditellum a broad 

 purplish brown band, limited by dorsal setae, appears on dorsal surface. ditellum, 

 XIII(XIV)-XVII, undeveloped venlrally. Male pores on slightly prominent papillae, 

 in a line with outer seta of ventral couple ; Sperm-duct pores slightly dorsal of these. 

 Prostomiwm continued by grooves about half-way over buecal segment, after a groove which 

 divides buecal segment into tioo halves. Setae in couples, upon prominent papillae ; those 

 of ventral couple nearer to each other than dorsal, especially behind ditellum. Dorsal pores 

 absent. Gizzard in VI ; in XV oesophagus becomes wider, and lias a much-foMed lining 

 membrane ; this is the equivalent of calciferous glands. Intestine begins in XVII. First 

 septum lies in front of gizzard, i.e. V/VI. Anterior septa not much thickened; those 

 between XI/XII, XII/XIII most. Dorsal vessel single ; hearts in X, XI, XII. Nephridia 

 paired, opening in front of dorsal setae ; the muscular terminal sac of nephridium has 

 a short caecum. A single pair only of sperm-duct funnels in X ; the sperm-sacs are 

 in IX, XI, racemose in c/uiracter. Spermiducal glands not very long ; penial setae 

 flattened, and widened out just before pointed free extremity, not ornamented. Sperma- 

 thecae with large diverticulum. Ilab. Rio Bruno, S. Chili; Corral, Valdivia. 



MICHAELSEN places the sperm-sacs in segments x, xi ; I think, however, that 

 the ' sperm-sac ' of segment x is a sperm-reservoir. The above description is mainly 

 taken from my own notes. 



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