8 Gustaf Eisen, 



The spiral muscles round the narrow tube, which can easely be contracted 

 serve evidently to keep the spermatozoa in the seminal vesicle and 

 prevent them from escaping in undue time. From the form and free 

 suspension of the inner duct, it may easely le seen that its free exterior 

 extremity can be considerably extended clear down to the penis proper 

 at the moment of copulation. 



The end of the penis is generally straight, slightly swelled, but is 

 also found helixlike (fig. 13. p.). 



The total absence of efferent funnels is a characteristic of great 

 value, not met with anywhere else in this class of worms, and which 

 places Eclipidrilus in a decidedly isolated position. The general structur 

 and arrangement of the generative organs as well as the simplicity of 

 the ventral vessel etc. shows this worm to be a true limicolide oligoch- 

 aete, and nearest allied to the families of Tubificidce and Lwnbriculidœ. 



The segmental organs are with certainty present in all the segments 

 posterior to the 9"' setigerous segment, but in the anterior segments I 

 have not yet discovered them. These organs are extremely delicate and 

 consist of a long slender and simple tube, whose exterior porus is found 

 just in front of the ventral spines and in a straight line drawn between 

 the spines, the efferent duct, the oviduct and seminal receptacle of the 

 same side (fig. 4). The interior end of each segmental organ is as usual 

 projected into or through the dissipiment of each anterior segment. The 

 neck of the organ is here considerably swelled, bottle like, and gland- 

 ulous, and the orifice itself is surrounded by large and small globular 

 and pellucid inflations. (Fig. 9). 



The spines are absent in the cephalic lobe and buccal segment, 

 but in all the other segments, we find 8 spines in 4 pairs, as in Lum- 

 bricididce. The spines are slightly 6' shaped and their free ends entire. 



Habitat. Eelipidrilvs frigidus is as j^et only found in the high 

 Sierra JVevada of California at an altitude of 10,000 feet or more. It 

 lives here in the bottom mud or more frequently yet among moss att- 

 ached to rocks over which the cold or even icy water is constantly 

 flowing at least during the warm season. The head end of the worm is 

 generally burrowed in the mud or moss, and the tail freely vibrating in 

 the water. 



