68 Bulletin 39 



DrilHa theobroma, n. sp. Plate 5, figure 11 



Shell siibfusiform; whorl 7 (apex broken) ; fasciole a narrow, 

 concave zone, not strongly differentiated from the rest of the 

 whorl, spirally sculptured and bordered above on the early spire - 

 whorls bj^ a sutural cord; sculpture consists on the spire-whorl 

 of about 10 low ribs, becoming more numerous and subobsolete 

 on the last; the spiral sculpture consists of raised, alternating, 

 revolving cords; there are 2 or 3 spiral cords on the early spire- 

 whorl, becoming 5 or more on the later; the last v/horl has about 

 10 spirals in addition to those on the anterior canal; between 

 each pair of the main or primary spirals there is a smaller, sec- 

 ondary spiral; base rounded or contracted to the slender anterior 

 canal. 



Length 21, diameter 7.5, last whorl 13 mm. 



It is possible that this species, belongs to the genus Glypho- 

 stoma, as the type specimen seems to show a slightly thickened 

 and inflated outer lip. The aperture is however so completely 

 filled with a rocky matrix, that this observation cannot be fully 

 verified. The axial sculpture is practically lacking from the 

 last whorl, leaving a surface simply marked with the rough 

 spirals. 



Gahm Stage: Bocas del Toro. 



Driliia aurantia, n. sp. Plate 5, figure 15 



Shell small, solid; whorls about 9; the nucleus consists of 

 about 1 5^ smooth, convex whorls which through the gradual in- 

 troduction of the ribs, followed by the spirals blend in with the 

 post-nuclear whorls; the anal fasciole is rather wide (about 1-3 

 of the spire-w^horl) and shallow; it uppears very early and car- 

 ries from the start a strong, sutural cord; the sculpture consists 

 of numerous closely spaced, linear ribs which are absent from 

 the anal fasciole; these ribs number on the last whorl about 21; 

 the spirals are uneven threads which are strongest below and on 

 the base; the fasciole also carries one or more fine threads except 



