372 
EDWIN LINTON 
DESCRIPTION OF THE SPECIES 
Graffilla gemellipara sp. nov. 
Small, rarely reaching 2 ram. in length; nearly linear, bluntly 
rounded at the extremities, often round-pointed at the posterior 
end, frequently bent a little to one side, making the outline 
arcuate, rather thick; ciliate throughout; color white, often tinged 
with yellow or greenish-yellow along the middle line; mouth small, 
ventral, near the anterior end; pharynx subglobose; esophagus 
short; intestine very difficult to distinguish in living specimens, 
extends along the dorsal side to the posterior end, its limits not 
always well-defined; eyes two, black, reniform, with a well- defined 
brain " behind them ; genital opening very small, ventral, situated 
at about the anterior third. There is a pyriform seminal vesicle 
which communicates with the genital pore by a short duct in 
which lies a plug-like penis. The ovaries are two ribbon-like 
bodies placed laterally and beginning about the anterior fourth and 
extending to the middle of the body. The yolk-forming cells 
(vitellaria) appear to be continuous with the ovary and are widely 
distributed. In all the larger specimens there were numerous 
young in various stages of development. The fully developed 
young, as a rule, lie together by twos inside a thin capsular envel- 
ope. They are ciliated and very active, turning round and round 
within the capsule, or, after breaking through the capsule, mxaking 
their way with ease through the mesenchyme of the parent. In 
the larger worms there are usually a number of small, irregularly 
coiled string-like bodies scattered throughout the body which have 
the appearance of being secretion products (figs. 16, 17). At 
first the idea that they are either of the nature of giant rhabdites 
or spermatheca was suggested. They appear to be collapsed 
embryonic capsules from which the embryos have escaped. 
Some specimens were collected which were immobile and con- 
tained but little beside the numerous active young. The latter 
are evidently not liberated until the reproductive powers of the 
mother are exhausted when they make their escape through 
the ruptured body-wall. Dimensions, in millimeters, specimen 
shghtly flattened; length 1.54; breadth, maximum, 0.65; breadth 
