11«^ «. GOTO. 



(Jdocohjlc, DicliilDpliura. ( hicMocoliilc, Moitucuhilc. and CoJicotijlc the 

 iVunt attenuated ])çrtion of the Ijody i.s entirely free from the vitel- 

 lai'iuni; the hinder caudal portion is also mostly free from it ; l)nt to 

 many species this statement does not a[)ply. In JJididophora h'lrodonis 

 which has a \ery elon^'ated hody, the vitellarium is wholly aljsent from 

 the whole slender posterior portion. In many species of Trisloiiunn 

 the vitellai'ium occu])ies not only the whole lateral portions of the hody 

 hut extends also into the median portion (7'. ocdic, T. yoiaii-ac). In 

 Microcotijlc, ( k'iocottjlc, J h'clidopJiord, Müiiocotijh\ CaHcohjli', KpilnlcUa^ 

 and in most species of 'rristoiiiaiii tlie \itellai'ium is present on the 

 d(jrs:d and Nenti'al sides of the Ixjdv alike; hut in ^[.iIni' the ventral 

 side is mcjstly free from it (I'l. ATI. hu\ 1). and in Trlsl. ncnlc the 

 d(jrsal side of the median ]jortion of the hod\' is entirely o(_'cu[)ied hy 

 tlie vitellarium. which thus leaves oid\- the ventral si(h; \^n' the testes 

 (IM. XXIII. fiu'. 7), In T. Xozdirui' too tlie vitellarium occu])ies in 

 the median ]>ortion of the hodv a |)osition nearer the dorsum than the 

 testes; hut in this species the ^•itelline lohes are more s[)arsely distrihuted 

 in this reiiion. 



The vitellarium consists of luimerous lol)es. which aiv in mcst 

 sfiecies more or less roiuideil. hut are tuhular in CdHcolijlc, so that in 

 this ueiius the N'itellarium ccjiisists of a system of fuhes filled with volk- 

 cells. In MoNocolj/lc. ( hichofnlijlc. Trisloiiiiiiii. ( klocüiijh\ and in most 

 species of Mifvorolißc and DicJidophora tliese lohes are very ch^selv au"- 

 gregated. and le;ive oidy a very thin laver of mesenchyma hetween 

 tliem. so that they are very diificult to distinguish fi-i3m each other in 

 sections (V\. IV. fig. 7; TI. XI, fig. 3; V\. \\Vl\. fig. 5); hut in all 

 the other species tlie lohes are separated from each other hy a more or 

 less thick layer of the inter^■ening mesenchyma. For instance, in 

 llcxacotijJv each lohe is surroumled on all sides hy the mesenchyma, 

 which thus completely separates it from its neighhours (1*1. XI, \v^. N; 



