168 THE AMERICAN NATURALIST. [VoL. XXXIV. 
the body. The egg-sac, which it may be assumed also appears 
in these specimens, I have not been able to observe. 
The external appearances of a parent stock with reproduc- 
tive products in the stages of development in which I have 
been able to observe them differ very little from a parent stock 
in which no such products are as yet present. Occasionally 
I have found that the anterior eyes appear somewhat larger, 
but no modifications of the parapodia, such as would indicate 
the epitokal condition so common in other syllidians, were 
observed. In all sexually mature parent stocks of Procerza 
I have found a third pair of eyes near the inner insertion of the 
palps. These are present as mere pigment spots in very young 
individuals of both Procerzea and Autolytus cornutus, but as a rule 
disappear or remain very inconspicuous in the adult. In several 
of the specimens in which the ova were nearest mature, conspicu- 
ous ventrally directed lenses were present. -A similar development 
of this third pair of eyes I have observed in the epitokal syllid 
Odontosyllis, taken at a time when the eggs have reached com- 
plete maturity; so that the appearance of this pair of eyes in the 
parent stock of Autolytus at this time might, I think, be looked 
upon as partaking of the epitokal condition in other syllidians. 
The percentage of parent stocks found with sexual products 
is by all odds too great to be looked upon as merely accidental. 
In a number of individuals examined, from all of which the 
stolons had recently been separated, and in which regeneration 
of segments was taking place (in this way eliminating as far 
as possible such individuals as are developing a first stolon), 
reproductive products were found to be present in as many as 
five out of twenty specimens examined for Autolytus Cornutus, 
and in as many as six and sometimes seven out of twenty speci- 
mens of Procerza examined. The stages of development of 
the reproductive products varied from early stages in which the 
presence of sexual cells could only be determined by the exami- 
nation of sections to the more mature ova already referred to. By 
eliminating the apparently less mature individuals and selecting 
only such as would indicate by their size and general appearance 
that at least a second stolon had been separated, as many as ten 
to twelve out of twenty specimens were found to contain sexual 
