6 CALIFORNIA ACADEMY OF SCIENCES. 
The exterior porus of the atrium is in Sutroa surrounded by strong muscu- 
lar swellings, and the atrium itself forms a kind of penis, which probably is to some 
degree projective. The exterior surface of the atrium is nowhere covered with 
clands, as is the case in Rhynchelmis, but consists of a long, narrow duct of a 
uniform width (Fig. 6, atr., and Fig. 14, atr.). No basal glands. 
The seminal vesicle consists of an enormous sac-like body, entirely filling 
the twenty segments occupied by the atrium and the efferent ducts. 1 did not suc- 
ceed in finding the placé at which it was attached to the atrium. 
The most characteristic interior organ, however, is the solitary body, for 
which I here adopt the name given by Vejdovsky, glandula albuminifera or albumi- 
nous gland. Iam, however, by no means fully satisfied of the functions of this 
organ, and its structure seems somewhat different from that of the albuminous 
glands of Rhynchelmis and Lumbriculus. The solitary albuminous gland of Sutroa 
opens in the center of the ventral part of the eighth segment (Fig. 14, gl. alb., and 
Fig. 10). It has the shape of a globulous body, connecting by a narrow neck 
with the body wall and opening through an external large porus. But the 
histological construction of this gland is quite different from the gland described 
by Vejdovsky in Lumbriculus* and in Rhynchelmis.+ 
In the latter two genera this organ is distinctly glandular, but in Suéroa it is 
of nearly the same construction as the receptacles, being covered by smooth epithe- 
lium, under which are found numerous long and narrow cells (Fig. 10). I have, 
however, no reason to doubt but that these organs are analogous in all the three 
genera. 
The receptacles in Sutroa consist of three pairs. In Rhynchelmis and Lumbricu- 
lus we find the receptacles open each in a separate porus; in Sutroa, however, there 
exists the great anomaly that all the six seminal receptacles open into the narrow 
neck of the above described solitary gland (Fig. 10, re. sem.). These receptacles 
consist of long narrow sacks, containing fully developed spermatozoa (lig. 8). 
Generally there are three pairs of receptacles, but in some specimens I found three 
receptacles on one side and only two on the other. Sometimes the interior end of 
a receptacle is forked; generally, however, they are entire. That these elongated 
bodies are real receptacles is proved by their being full of spermatozoa fully devel- 
*Vejdovsky, System Cer Oligochwten. Taf. XII, 16. g. alb. 
{Same. An. stud. RKhynchelwis. ‘Taf, XXIII, Fig. 17. 
