532 PROCEEDINGS: BOSTON SOCIETY NATURAL HISTORY. 
ous individuals were obtained in the original locality, but of much 
larger size than those found by the Challenger party. These worms 
occurred not only near the shore but also well up on the side of the 
hill where the soil was comparatively dry. On his return to New 
Haven, Professor Verrill very kindly brought a number of living 
specimens to the writer and these were kept for some weeks in the 
dry earth in which they came from Bermuda, a few drops of water 
being added from time to time to prevent complete desiccation. 
These specimens were subjected to rough treatment by being placed 
on glass slides on numerous occasions and examined under the 
microscope. They perished eventually, evidently from lack of a 
supply of suitable food. 
It was partly with a view to further investigations on the anatomy 
and development of this form that the writer visited the Bermudas 
in June and July, 1903. 1 
At this time an abundance of material was obtained, for the spe¬ 
cies was found to be widely distributed on the islands, occurring on 
the north as well as on the south shore, and was common along the 
borders of several of the larger mangrove swamps. At this season 
of the year the worms were found to be sexually mature, their bod¬ 
ies being crowded either with ripe eggs and spermatozoa or with 
embryos in all stages of development, for the species proves to be 
viviparous, giving birth to young worms of comparatively large size 
fully provided with nearly all the organs of the parents except the 
reproductive glands. The general course of development of these 
embryos could be followed with the greatest ease by making serial 
sections of the adult worms in which they were contained. 
Examination of the sexual glands of numerous individuals showed 
many with these embryos in various stages of development, while 
others were provided with ova only. Still other specimens of small 
size were completely filled with ripe spermatozoa. Moreover, a 
number of individuals — the largest specimens collected,— had 
nearly mature embryos and in addition small gonads of both kinds 
of sexual products. In some of these latter the spermatozoa were 
fully formed. 
The species has therefore a peculiar interest because of the fact 
1 The writer is greatly indebted to Prof. E. L. Mark and Prof. C. L. Bristol 
for the excellent facilities afforded by the newly established Bermuda biolog¬ 
ical station for research. 
