NEW SPECIES OF OCNERODRILUS. 263 



as in that species. The length of the spermatheca is not 

 quite equal to that of the oesophageal diverticulum, while 

 in O. Rosiv it is longer than the said diverticulum. These 

 measurements refer to sexually mature species. The 

 lower part of the spermatheca is narrower and muscular, 

 the muscles being arranged in two directions. The outer 

 circular layer is the thickest, and reaches only to the 

 pouch part of the spermatheca. It contains large round 

 nuclei. The longitudinal layer extends all around the 

 spermatheca, and is narrower than the inner epithelium 

 of the pouch. The cells of the epithelium are narrower 

 and less regular than in O. Beddardi. 



The oesophagus is contracted at the septa similarly as in 

 O. Hendriei and Rosa. The sacculated intestine begins 

 in somite xii, and differs in this respect from O . Rosa , 

 in which species it commences in somite xiii. 



The sperm-sacs d^re large, and in mature specimens con- 

 stant in size and are characteristic of the species. The 

 one in somite ix consists of an enormous sac, not lobed, 

 which fills the whole somite. The sperm-sac in somites 

 X and xi are narrow, but long, reaching from the dorsal 

 to the ventral parietes. The sperm-sac in xii is lobed, 

 and attached in the usual way to the anterior septum. In 

 O. Rosa the sperm-sac in somite x is generally wanting, 

 and always, when present, is of very small size. 



The vascular system resembles that of other species, 

 but there is no connecting vessel in somite ix, as in O. 

 Hendriei and limicola, which former species the present 

 form otherwise much resembles. From O. limicola, which 

 possesses this connecting vessel, the present species is dis- 

 tinguished am.ong other things by its almost entire septal 

 glands, by one pair of prostates, etc. 



The lower part of the sperm duct is muscular, enlarged 

 and shuttle-like, in very much the same way as in O. 



2d Ser., Vol. III. ( 20 ) January 19, 1893. 



