554 THE ANATOMY OF INYERTEBRATED ANIMALS. 



are any cilia visible in them ; but the minute molecules which 

 float in the clear fluid which they contain are driven to and 

 fro, apparently by the contraction of the body. Inferiorly, 



Fig. 157. — Echinorhynchus.—K.. Diagram exhibiting the relative position of the or- 

 gans : a, proboscis ; 6, its stem ; c, anterior enlargement of the body ; /, neck or 

 constriction between the anterior enlargement and the rest of tbe body, e?/ e, 

 posterior " funnel ;" gr, meniscus ; A, superior oblique tubular bands; yfc, inferior 

 muscles of the proboscis : /, m, genitalia ; o, penis, or vulva. B. Lower extrem- 

 ity of the stem of the proboscis : a, ganglion ; h, vascular space ; c?, outer coat ; 

 c, inner wall ; e, tubular band, with the nerve ; A,/, muscular bands ; ^, suspen- 

 Borium of the genitalia. C. Part of the female genitalia : a, ovary ; h b, ducts 

 leading from ovary to uterus, spermiducts (?); c, open mouth of oviduct; d, e, 

 uterus and vagina. 



the vessels all terminate in blind canals, disposed around the 

 margin of the posterior funnel. Internal to the vessel lies a 

 double layer of anastomosing muscular fibrils, the external of 

 which are circular, while the internal are longitudinal.* The 

 cavity of the body is filled with a fluid, in which the ova, or 

 spermatozoa, float, and, at its anterior extremity, two elon- 

 gated oval bodies depend from the parietes, and hang freely in 

 it. These are the lemniscl / they are traversed by vessels 

 continuous with those of the parietes. The axis of the pro- 

 boscis is continued downward into an elongated subcylindrical 

 stem, rounded below, which hangs down like a handle into 

 the cavity of the bod}'. The extremity of the stem is con- 

 nected by broad retractor muscles with the parietes, and 



' See, for an account of the remarkable structure of these muscles, Schneider, 

 " Ueber den Bau der Acanthocephalen." (" Archiv fiir Anatomic," 1868.) 



