894 REPORT OF COMMISSIONER OF FISH AND FISHERIES. [16] 



number of species has been studied new and more distinct character- 

 istics maj^ be discovered. A prominent feature of the genus is also the 

 elongation and narrowness of the copulative organs. In all other genera 

 except Gamptodrilus said organs are much shorter, especially so the ovi-« 

 duct. In luhifex we find the shortest and widest oviducts; in Limno 

 drilus and Camptodrilus the longest and narrowest. 



In the following synoptic table the three species, L. HoffmeisteriGl-A^.^ 

 L. Udelcemianus Clap., and L. Glaparedianus Eatzel, are not classified, 

 have not had opportunity to see those species myself, and as some points 

 in the description of their reproductive organs, &c., are wanting, it ha 

 as yet been impossible to arrange them systematically among the othe 

 species. They seem, however, to be nearest related to L. monticola an^ 

 alpestris : 



A. 1 lie oviduct is single. The upper end of tlie penis sheath furnished with a crown 

 of star-like concretions. 



LiMNODEILUS ORNATUS. 



B The oviduct is double. The upper end of the penis sheath not furnished with 

 star-like concretions. 



1. The penis prope* projecting outside the penis sheath and here forming a 



globular head. Inner oviduct muscular. 



LiMNODRILUS StEIGERWALDII, 



2. The penis proper not projecting outside the penis sheath, and its lower 



end not forming a globular head. The inner oviduct is not muscular, 

 but chitinous. 



a. The lower end of the penis proper is truncate and somewhat wider. The 

 lower end of the interior oviduct is wider than its middle. 



LiMNODRILUS MONTICOLA. 



C. The lower end of the penis sheath is pointed. The lower end of the interior 

 oviduct is wider than its middle. 



LiMNODRILUS ALPESTRIS. 



c. The lower end of the penis proper is pointed or rounded. The lower end of 

 the oviduct is much narrower than its middle or upper part. 



LiMNODRILUS SiLVANI. 

 LiMNODRILUS ORNATUS n. Sp. 

 (PI. IX; Fig. 8.) 



Nervous system. — The cephalic gcmglion is broadest posteriorly, the 

 two lobes being well rounded and separated, but the sinus between them 

 is rather shallow (Fig. 8c). 



Generative system.— The penis is long and slender, broadest at its 

 upper end, and from here gradually tapering towards the apex, which, 

 however, is not tapering, but cylindrical. The penis sheath is long, 

 cylindrical, trumpet-shaped at both ends, and slightly narrowest at the 

 middle. Its upper end, at the entrance to the oviduct, is furnished with 

 a crown of star-like concretions, of a brown, chitinous consistence (Fig. 

 8(7, crn.) The oviduct is single, sack-like, and longer than the penis 

 sheath. In the same no cellnuclei are visible. Surrounded by longi- 

 tudinal muscles. The receptacle is elongated, and of a flask-like shape, 



