566 PROCEEDINGS: BOSTON SOCIETY NATURAL HISTORY. 
tlie duct leading from the pouch to the anterior proboscis chamber 
and is thence transferred to the apex of the basis, which has already 
been formed in the manner above described. The central stylet is 
thus supposed to be replaced from time to time by one of the acces¬ 
sory stylets. 
Although it cannot be stated positively, a study of the developing 
stylet in Geonemertes indicates strongly that the central stylet is 
actually formed in situ on the apex of the basis. In Carcinone- 
mertes, in which no accessory stylet pouches or stylets are present, 
the central stylet must of necessity be formed at or near its ultimate 
position at the apex of the basis. This would support Montgomery’s 
view that at least in certain forms the central stylet originates 
independently of the accessory stylet pouches. 
Habits. 
The species is found in abundance at several places on the Ber¬ 
muda Islands, but so far as known, occurs only along the shores of 
mangrove swamps and on the adjacent hillsides. In the summer it 
has been found only in the moist soil near high-water mark, 
although it probably also occurs higher up on the hillsides, where it 
has been found in the spring months. In the summer these hill¬ 
sides become very dry at the surface so that the nemerteans prob¬ 
ably follow the burrows made by the earthworms deeper into the 
soil, where moisture is more abundant. 
Near high-water mark on the edge of the mangrove swamps the 
soil consists mainly of black mud succeeded by a dark or reddish 
loam farther up the banks. Under stones, sticks, and rubbish of 
various sorts in such localities occurs an abundance of earthworms 
of various species, of which some are indigenous and others im¬ 
ported accidentally. Associated with these earthworms are nema¬ 
todes and sometimes insects, as well as the species of nemertean 
which forms the subject of this investigation. 
The nemertean is easily distinguished by its pale gray, whitish, 
or orange color, and by the large whitish proboscis which it everts 
when irritated. It occurs not only above high-water mark but also 
for some distance along a zone which is covered for a short time 
each day with sea water. This is also true for one or more species 
of earthworms. Individuals found between tides are as a rule of 
