12 EISEN, PRELIM. REPORT ON GEN. AND SPEC. OF TUBIFICIDEZ. 
vessels in the ”7th, 8th, 9Ith setigerous segments. The ova 
are situated behind the cingulum in the segments 19 to 22. 
Numerous perigastric cells. Body about 25 m.m. long by 1 
m.m. wide. 
Habitat: California, San Francisco, in a spring at the 
Marine Hospital lake. 
I. fragilis n. sp. 
The efferent duct is longer than the atrium, oviduct and 
penis together. "The penis 1s comparatively longer than in 
the preceeding species. No penis-sheath. The oviduct is 
funnel-shaped, chitinous, surrounded by longitudinal muscles. 
The receptacle is straight, with a very large, perfectly glo- 
bular top, of a very pellucid consistency. No comb-like 
spines, only hair-spines and forked ones. The length of the 
body about 15 m.m. and the width about 0,5 m.m. The 
body is very slightly tapering, nearly cylindrical. That of 
the former species was decidedly thickest on the middle and 
considerably tapering towards both ends. 
Habitat: California, Sierra Nevada, Fresno Co, in the 
bottom of running springs at an altitude of 7000 feet. 
Hemitubifex n. gen. 
The cephalic ganglion emarginated both in front and 
behind. The upper end of the atrium is enlarged to a glo- 
bular chamber or ”vesicula seminalis” on which the prostata 
is grafted. The lower end of the atrium is glandular. The 
penis-sheath is chitinous, shorter than the oviduct. The 
oviduet is double, both sheaths being chitinous and funnel- 
shaped, and of nearly exactly the same shape. The exterior 
one is surrounded by longitudinal muscles. The receptacle 
for the spermatozoa is furnished with several winglike glands 
round its base. The top of the receptacle is enlarged and 
constitutes the receptacle proper. 
The spermatophores are straight or slightly bent. The 
spines are of two kinds: hair-spines and forked spines. In 
some individuals no hair-spines are met with, and in others 
they are very sparingly distributed. No comb-like spines. 
