102 



SYSTEMATIC ZOOLOGY 



several details; the trivium is usually flattened, often the lighter 

 in color, and the ambulacral feet may be confined to that region. 

 A madreporic plate is scarcely ever found on the surface of the 



rdd ami 

 ring ves 



n blvee 



pol v&s 



storrv 



iit i/&3 — , 



a en op 



ratf, oss 

 — inter oss 



qen.doc 

 - 77tad.ca.rt 

 int ves 



Long ma,5 — r V\ j 



gen.gl 



cl.op 



FlG. 94. Internal organs of a holothurian as scon when the bodv wall is divided along 

 the middle of the dorsal surfaci . body wall; circ.musc, circular layer ot nuis 



cl, cloaca; cl.op, cloaca! opening; a uvieran organs: gen. du, genital duct; gen.gl, 



germ-gland; .. genital opening; int, intestine; inter.oss, interambulacra! 



int.ves, intestinal vi ongitudin; band ; mad.can, madreporic cat 



vies, mesentery; pol.ves, Polian vesicles; rad.amb, radial ambulacral vessels; rLbl.ves, ring 

 blood vessel; resp, respiratory trees; 1 ring vessel of ambulacral system; 



stomach. (After Leuckart, from Parker and Haswell's Text-book.) 



