294 Illinois State Laboratory of Natural History. 



divisions, is composed entirely of fibers with the excep- 

 tion of a few cells in the dorsal part. Groups of cells 

 are situated respectively in front of and behind the 

 point of union of the commissures with the ventral 

 chain. The pharynx extends through II— V and is fol- 

 lowed by the oesophagus in VI and YII, and in VIII 

 by the intestine, which, as indioated by the chloragogue 

 cells, commences in that somite. The septal glands are 

 large in IV— VI, and slightly developed in III. 



Beginning with the eleventh somite, paired appenda- 

 ges of the dorsal vessel with several caecal branches are 

 present. Nephridia are contained in the same somites 

 with the gonads at the time of maturity of the latter. 

 No especial modification of the epidermis to form a 

 clitellum has been noticed. Albumen glands are want- 

 ing. Two pairs of testes are present in IX and X and 

 two pairs of ovaries in XI and XII. The male pores 

 were determined with certainty in but three specimens, 

 in two of which the pores were upon X and in the other 

 upon XI. The atria are similar in form and in the 

 structure of the walls to those of Z. variegatus as de- 

 scribed by Hesse (4, p. 358) and by Vejdovsky (19, p. 

 81). Whether or not a definite penis is developed I am 

 unable to state. The funnels of the sperm ducts are 

 borne upon the posterior walls of IX and X. The sperm 

 ducts have not yet been followed throughout their en- 

 tire course. A pair of elongated sperm sacs communi- 

 cate with X and extend backward for a varying num- 

 ber of somites, in some cases as far as XX. Well- 

 developed spermathecae were found in but one specimen, 

 and in that did not contain spermatozoa. There are 

 five pairs in XI— XV, with their pores dorsad to the 

 ventral setae and situated similarly to those of 

 L. varlegatw. In another example vestiges of these 

 organs were present in XI— XV, while the specimen hav- 

 ing male pores upon XI had traces of spermathecae in 

 XII— XVI. The oviducts are short and open at the 



