20 EISEN, PRELIM. REPORT ON GEN. AND SPEC. OF TUBIFICIDA. 
duct is double, the interior one is about ”/, as long as the 
penis; the wanting quarter being at the upper end. Seen 
from the side it resembles somewhat an arrow-quiver; 
when seen from the front it is found tightly to eneclose the 
exterior end of the penis-sheath, but its upper third is wider 
than the upper half of the penis-sheath. The exterior ovi- 
duct is more sacklike and somewhat loosely enclosing the 
interior genital organs. The receptacle is furnished with a 
large upper sacklike enlargement, which in the smaller form 
is bent over. The segmental organs are narrow and long, 
and not surrounded by globular cells. The integument is 
extremely tough, giving the worm a consistency nearly equal 
to that of a thread. 
Of this species there exist two different sized forms: 
One 18 c.m. long avd 2 m.m. wide; an other 5 c.m. long by 
1 m.m. wide. Both forms differ anatomically as described 
above, but are connected by intermediate forms, which may 
perhaps be considered as beginning species. 
Habitat: California, San Francisco. The large form found 
only in the Marine Hospital pond. The small form in the 
said pond, Laguna Merced, and Laguna del Tache. 
Finally I will make a few remarks on the two species 
described by ÖCLAPAREDE, viz. 
L. Udekemianus CLAP. 1862. 
Syn.: LC. Udekemianus ÖLAP. fe pas24D: 
L. Hoffmeisteri CLAP. 1862. 
Syn.: L. Hojfmeistert  CLAP. 1. c. pag. 248. 
It is pretty evident that CLAPAREDE did not discover the 
interior entrance to the oviduct in Limnodrilus. In referring 
to his above cited work, pl. I. fig. 1—4 we find the penis- 
sheaths ce” and c figured as if they were entirely enclosed in 
the penis, instead of enclosing the same; and the oviduct d” 
is seen to connect with the exterior coating of the atrium, 
which I have found in all the species I have investigated 
not to be the case, but the lower end of the atrium enters 
the penis-sheath and forms here a penis proper. The sheath 
d", to judge from analogies with my species, does not connect 
