554 THE ANATOMY OF INVERTEBRATED 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. Infer iorly, 



Fig. 151.— Ec/iinoJ'JiyncJnifi.— A. Diasrram exhibiling the relative position of the or- 

 gans : a, probosci>^ ; 6, its stem ; c, anterior enlargement of the body ; /". neck or 

 constriction between tbe anterior enlargement and the rcstof tlie body, c?,- e, 

 posterior "funnel ;" <7, meniscus; /i. superior oblique tubular bands; A-, inferior 

 muscles of tlie proboscis ; I, m, genitalia ; o, penis, or vulva. B. Lower extrem- 

 ity of tlie stem of the proboscis : a, ganglion ; b, vascular space ; d, outer coat ; 

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

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

 leading from ovary to uterus, spermiducts (?); <?, 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 lemnisci ; 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 body. The extremity of the stem is con- 

 nected by broad retractor muscles with the parietes, and 



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

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



