326 Anatojuical Notes on Sutroa Alfestris. [zoe 



lar system consists of primary and secondary vessels, tlie former 

 being the ventral and dorsal vessels. The ventral vessel branches 

 in somite V, the branches being connected with the dorsal vessel 

 through one pair of secondary vessels in each somite. Of the pos- 

 terior perigastric vessels, both pairs in each somite connect the 

 dorsal and ventral primary vessels. The anterior pair is ramified, 

 of the posterior pair only the dorsal part is ramified. 



In Sniroa rostrata the ventral vessel branches in somite VIII, 

 the branches connecting with each other through one secondary 

 vessel m each somite, but do not connect with the dorsal vessel 

 The perigastric branches of the dorsal vessel are ramified, but do 

 not connect with the ventral vessel. 



In mynchelmis limosella (according to Vejdovsky) the ventral 

 vessel branches in somite V, each branch connecting with the dor- 

 sal vessel through one pair of simple secondary vessels. In the 

 eight anterior somites the perigastric vessels consist of only one 

 pair, while m the posterior somites there are -two pairs in each, 

 the anterior pair which is not ramified connecting with the ventral 

 vessel, the posterior ramified pair being entirely free. The dorsal 

 vessel IS covered with opaque cells. The ventral vessel is trans- 

 parent and entirely devoid of cells. 



The alimentary canal is very simple. In the anterior somites It 

 consists of a simple tubular duct or intestine. In somite XII 

 this duct changes to a sacculated intestine covered with gastric ves- 

 sels (hig. 27)._ In Sutroa rostrata this sacculated intestine com- 

 mences in somite XIII. 



Nervous SvsTEM-resembles that of Sutroa roslmla, but the 

 cephahc ganghon ts more compact and exiiibit. two large anterior 

 obeswhtchem.t a number of nerve thread, towards ie cephalic 

 lobe (Fig. 9), or fihform part ol the prostomium 



'"*'./''' ^"7"'"" '"" """ucive. The generative organs 

 are sperm-sacs and testes, ovaries, albumen glands, and prostata. 



2^L 7 ' ■' "8^' '"'""'^""=' '=«■'='■'="' ducts and sperm- 

 or«a?;„ ■^f T" ™ ™ ''' "'* ''^ ^-^S^ds the true inter- 

 necessary " ""''°" "^'"= =" ""^^ 'J^'^'l^d *-riP'i°" - 



sit,med'?'™'T ™"''" °' ""^ P''''- °f '"«'= ^'o-S^'^d bodies 

 situated m som.tes .3-20, They are the largest and t^ost conspic 



