1892.] 



SPECIES OF EARTHWORMS. 



673 



are attached to the posterior wall of their respective segments, as 

 they are in Acanthodrilus anneetens and in Octochcetus multiporus. 



The racemose sperm-sacs are in xi., xii. 



The spermatothecae are elongated pouches in viii. and ix. ; they 



Fig. 2. 



-rM 



OctochcBtus thomasi, dissected to show the principal organs. 



G, gizzard ; B.v, dorsal vessel ; L.v, lateral vessel ; H, hearts; 

 Sp.s, sperm-sacs ; Ca, calciferous gland ; At, atria. 



appear to have numerous minute diverticula crowded round the 

 duct near to its external opening. 



The atria do not extend Ijeyond their proper segments. A number 

 of strong muscular bands, such as occur in Octochcetus multiporus, 

 pass from the lateral to the ventral walls of segments, and serve, no 



