144 



terior margin distinctly emarginate, lateral margins slightly divergent 

 caudad. Peptonephridia lacking. Dorsal vessel varies slightly in po- 

 sition of origin, arising in XIII-XIV. Xephridia with large post- 

 septal part and very small anteseptal part which consists only of 

 nephrostome; efferent duct arises from ventral surface of posterior 

 part of postseptal part. Testes multilobed, with about nine lobes on 

 each side of body; each lobe capped by a small sperm sac. Spermi- 

 ducal funnel cylindrical, four to five times longer than diameter, and 

 strongly l^ent at middle ; collar present, slightly reflected, slightly wavy 

 in outline, and set off from body of funnel by slight constriction. One 

 pair of spermathecse in V; without diverticula and each consisting of 

 a well-developed ampulla and a short duct; ampulla consisting of an 

 expanded, barrel-shaped, thick-walled and much narrower ental re- 

 gion which is reflected cephalad before uniting with digestive tract; 

 duct not sharply set off from ampulla, much shorter than ampulla and 

 surrounded by w^ell-developed gland which shows a number of lobes 

 arranged in form of rosette; ectal opening laterad and near IV/V, 

 ental opening on lateral wall of digestive tract in posterior part of 

 V. Ventral glands in XIII and XIV; differ slightly in shape in the 

 two somites; surround ventral ganglia closely on ventral, lateral, and 

 part of dorsal surfaces, leaving only median dorsal line free. 



Described from thirty-two sexually mature specimens. Many other 

 specimens were examined in determining external characters. Type 

 and paratypes in the collection of the writer, and paratypes in the 

 collection of Professor Frank Smith. 



The specimens which are the basis of this description were col- 

 lected June 22, 191 1, by A. A. Girault, in sprinkling filter No. 5 of 

 the Chicago Sewage Testing Station. They occurred in great abun- 

 dance in the sludge which covered the limestone rocks composing the 

 filter bed. A complete description of the habitat of these worms is 

 given in another part of this paper (pp. 180 -184). 



AfUnities. — This form is easily separated from the other known 

 American species, and the differences are so distinct and so numerous 

 that it can scarcely be said to have any close relatives among the 

 American forms. When compared with the foreign species of this 

 genus it appears to resemble L. litoreus Hesse, L. suhterraneus Vejd., 

 L. lineatus Miill., L. verrucosus Clap., and L. tenuis Ude. There are, 

 however, a number of distinct differences in each case and, further- 

 more, the descriptions of the above-named species are very brief and 

 make no reference to some characters which are now considered to be 

 of use in separating species. When these descriptions are made more 

 complete it is reasonable to expect that other points of difference not 

 yet known will be found. 



