ra) 
~2 
“2 
LYMNEID/ OF NORTH AMERICA. 
from the side; retractor muscles of penis two in number, very long 
and narrow, ribbon-like; one muscle enters the penis-sac and one the 
head of the penis; protractor muscles very small, five in number, three 
on the posterior and two on the anterior face of the penis-sac. 
Female organs: Oviduct not differing from that organ as found 
in other Lymnezas; receptaculum seminis not remarkably large, ovate 
or pyriform, with a duct 3.00 mill. long joining the oviduct .25 mill. 
from the vaginal opening; albuminiparous gland of the usual form; 
first accessory albuminiparous gland large, pyriform, a little elongated, 
its proximal end narrowing suddenly toward the vaginal portion of 
the oviduct. The receptaculum seminis is orange in color and the 
albuminiparous gland is yellowish. 
The genitalia exhibit some variation. The retractor muscle of the 
male organ may be separated or the penis retractor may enter the 
penis-sac retractor about half its length from the columellar muscle. 
(Pl. XIV, fig. G, 1, 2.) The first albuminiparous gland also varied 
in one specimen, being irregularly quadrate instead of regularly pyri- 
form. In another specimen the prostate was flattened and broadly 
pyriform when viewed from above, but elongated when viewed from 
the side. (Pl. XII, fig..C.) The majority of specimens examined, 
however, were as shown in figure C, plate XI. 
Several measurements of the genitalia gave the following results. 
(Dissections Nos. 23167, 23168, 23169, 23170, 23177, 23178, 23179.) 
The uniformity of the majority of the measurements is noteworthy. 
Penis- Rec. Prost. Vas. Ret. mus. Ret. mus. 
Penis. — sac. sem. duct. def. Penis. Penis-sac. Shell. 
2.79 2.00 3.00 1.00 5.00 ARO) ries 9.50 Cayuga Lake’ 
2.00 1.90 3.29 1.00 5.00 1.10 ET (2) 11.50 ~ 2 
2.00 1.90 3.25 1.00 5.00 1.10 1.75 10.50 Sea Breeze’ 
3.00 2.00 3.00 1.00 5.00 1.10 IW afis 11.50 - 2 
2.75 2.00 3.00 1.00 5.00 1.10 AS 11.50 Des Moines 
3.00 2.20 3.00 1.00 5.00 ie 1.50 13.00 ad 
2.00 2.00 3.00 1.00 5.00 1.10 1.50 11.50 
2.00 2.00 3.00 1.00 5.00 1.10 1.50 12.00 Narrow form 
1.10 1.10 3.00 1.00 3.00 1.10 1.00 9.00 “sy 
evo 1.50 3.00 1.00 3.00 1.10 1.50 10.00 
On May 15, 1907, several egg masses were laid by this species 
in an aquarium; the measurements of the masses and the number of 
eggs in each are given below: 
800x2.00 mill., 30 eggs; 7.50x2.50 mill., 45 eggs. 
RANGE (Figure 28): From the Atlantic to the Pacific oceans, 
1Animals killed in June. 
