132 



IXVERTEBEATE ANIMALS. 



pseudohsemal system being visible through the transparent in- 

 tegument. 



Fig. 83. — 0)igitcha.>ta. A, Anterior portion of TuM/ex rivulorum, enlarged; j) 

 Pliarynx ; i i Alimentary canal ; d d Dorsal vessel ; h One of tlie " hearts " or con- 

 tractile dilatation.s of the pseudoheenial vessels. B, Anterior portion oi Lumbric'us 

 terresiris, laid open and enlarged : o Moutli ; p Pliarynx ; g Gullet ; m (Esophageal 

 glands ; c Proventriculus ; s Gizzard ; i Intestine ; h One of the " hearts," borne on 

 tlie side of the dorsal vessel ; t Testes ; sp Spermatliec^. (After Lankester.) 



Order III. Polvch^ta. 



In the so-called Polychoetous Annelidas, the animal is furnished 

 with locomotive organs in the form of " foot-tubercles," carrying 

 tufts of bristles (fig. 81). Branchiae are generally present, in the 

 form of outgrowths of the integument, richly supplied with 

 branches of the pseudohaemal vessels. Tlie Polychastous Annelides 

 are all marine, and are of very varied habits. They may be con- 



