Auloclrihis 601 



nital setae only occur in A. pigueti, usually two in bundle (Fig. 

 32, s. g.), abolit 73 ^t. long, of a shape as Fig. 22 shows. The setae 

 and their glands lie at the ground of a round bladder-like dépres- 

 sion of the skin, in which gathers the sécrétion of the glands being 

 in full activity (Fig. 20, 21). Maie openings near the ventral 

 setae of segment VII, in A. limnobius (Fig. 4, (^) and A. pluriseta 

 (Fig. 53, çf) paired, in A. pigueti (Fig. 12 — 15, çf) unpaired, ari- 

 sen from uniting of both paired ones, in the middle of the ven- 

 tral surface of this segment. In mature spécimens of A. Umnohius 

 large penis-masses cause protubérances of the flanks of the body 

 at their sides (Fig. 4). 



Feraale organs. Ovaries (Fig. 46, ovr.) in segment VIL 

 Female openings on the limit of segments VII and VIII, in 

 the same longitudinal Une as the maie ones (Fig. 4, 12, 53, Q). 

 Spermathecae in segment VI. They resemble long, wide sacs, 

 being wider at the inner end in A. limnobius (Fig. 5, 6) and narrower 

 in A. pluriseta (Fig. 47). Their distal (efferent) parts — vesti- 

 bula of the author — are in both thèse species very small. In 

 A. pigueti (Fig. 25, 26, 29), on the contrary, the bladder-like vesti- 

 bula are much wider than the long tubular spermathecae. External 

 pores of them lie in front of the setae, in A. pluriseta (Fig. 54) 

 and A. pigueti (Fig. 24) near the ventral setae, in A. linmobiiis 

 (Fig. 7) near the dorsal ones. Sperm in the spermathecae was only 

 seen in A. limnobius^ in form of an irreguîar mass. 



Sperm -sac and egg- sac unpaired, reaching backwards the 

 end of segment VIII. Clitellum occupies segments VII and 

 VIII (Fig. 13, cl). Ventral setae in mature spécimens in A. pigueti 

 are missing in segments VI and VU, in A. pluriseta only in seg- 

 ment VII (in advanced maturity). in A. limnobius^ reduced in num- 

 ber, in the same segment. 



The animais in question live in thin long mud-tubes (in size 

 according to the size of the animal), sticking vertically in the 

 mud- ground and being prominent at a considérable distance 

 (Fig. 41). In good natural conditions they hide entirely in their 

 tubes: no part of the posterior end of the body stands outofthem, 

 except in the moment of évacuation. Having left their tubes they 

 undertake characteristic movements, arcuating rapidly the body in 

 one and then in the opposite direction (Fig. 43), but on the same 

 place. 



