4 ON SOME TERTIARY FOSSILS, 



This fossil differs from those previously described, in its short 

 posterior side and the absence of any groove within the angle. 

 It is also of tumid shape and the ribs are regular. 

 Crossea parvula. PL 1, tig. 7, 

 Testa minuta, oblique discoidea, late profundeque umbilicata, solida, 

 nitente; anfr. 3}j, rotundatis, regular iter, concinne, spiraliter striatis, 

 apice prominulo ; apertura exacte orbiculata, labro erassa, postice 

 producto, cum margins umbilici ' conjunct o, labio immerso, antice incrassato, 

 producto, angulato, umbilico, concur o. 



A minute NaticaASk.e shell, with a wide umbilicus and the 

 columella produced into a thickened anterior angle, the labrum 

 is also produced very much posteriorly, so as to be continuous 

 with a solid margin, which surrounds the umbilicus ; the aperture 

 is perfectly round and solid, which is the character of the whole 

 shell. There are also signs of fine punctate dots in the grooves, 

 which neatly ornament the lower whorls, like C. concinna Angas 

 of Port Jackson. Crossea may be said to be a characteristic 

 Australian genus. The peculiar angular extension of the 

 columella easily serves to distinguish it. This is the first instance 

 of its being found fossil. It comes very close to the existing 

 species, but is very much smaller. 



Trivia minima. PI. 1, fig. 8, 8a. 

 Testa pan a, late ovata, globosa, nitente, spiraomninoocclusa; costis 

 distantibus, medio sulco conspicuo separatis, aliquando bifurcatis, 

 aliqnando costis brevioribus inter calantibus ; apertura angusta, utrimque 

 curvata, labio angulato ; labro incrassato, lato, sabvaricoso. Long. 6, 

 lat. 51 alt., 3£. 



Shell small, broadly ovate globose or ventricose, spire quite 

 concealed ; ribs distant, well raised and conspicuous, separated 

 on the back by a conspicuous groove, some bifurcating and some 

 shorter ribs sometimes intercalated in the interstices ; aperture 

 narrow, curved at each end ; lip angular, the ends of the ribs 

 forming the teeth, which are somewhat close ; the labrum is 



