THE MOLLUSCA—HEDLEY. 445 
feebly divided from one another, that they seem rather to be a 
continuous keel, like that of 7’. corrwgatus, in process of breaking 
down into beads. The earlier adult whorls are ornamented by 
two bead-rows. Between them there arises in the antipenultimate 
a thread, which gradually increasing becomes a full grown row in 
the last whorl ; the addition of a median and two basal rows brings 
the number of rows on the last whorl to six. Tryon states that 
the “three anterior ones are unarmed,” but all are beaded in the 
example before me. 
Fig. 31. 
The anal notch is simple and comparatively shallow. The 
protoconch has five whorls, the first hemispherical and smooth. 
the others bicarinate and obliquely crossed by rather coarse bars 
which do not bead the carinae. The adult sculpture suddenly 
commences in the sixth whorl with a row of small beads above 
and a large gemmed ridge below. The latter is remarkable in 
several specimens before me for its white colour, giving the shell to 
the unaided vision a distinct white collar beneath the acicular 
apex. Tryon gives the length as 8mm. Of the examples before 
me the New Caledonian measure 45, the Papuan 4, and the 
decollated shells from Funafuti 34mm. 
Two decollated specimens occurred to me in the Funafuti 
lagoon. I have also taken the species between tide marks in Port 
Moresby, British New Guinea. A Papuan specimen supplied 
the material for the above account of the apex, missing in Funafuti 
and New Caledonian examples. 
TRIFORIS THETIS, Sp. NOV. 
(Fig. 32). 
Shell small and slender. Colour uniform cinnamon-brown 
except a patch of dark chocolate on the columella. Whorls 
fifteen. Protoconch five whorled, the later three bicarinate, 
