816 Transactions. —Geology. 
a whorl. Suture well marked. No posterior band-on the whorls. Aperture 
ovate ; the columella twisted, produced into a short nearly straight canal. 
No posterior sinus. 
Length, ‘53 inch ; breadth :15 inch. 
Locality. Wanganui. 
Distinguished from T. tristis by the stronger and smaller number of the 
longitudinal ribs. 
Clathurella hamiltoni. Pl. xviii., fig. 7 
Shell ovato-fusiform. Whorls 7-8, rather ionli behind; the first 
24 embryonic, smooth; the others strongly longitudinally ribbed and 
crossed with fine spiral liræ. There are about 12-15 rounded, longitudinal 
ribs in a whorl, and the spiral liræ are small and close set. Aperture ovate, 
rather angled behind; posterior sinus obsolete; the anterior end deeply 
notched ; inner lip reflected over the columella. 
Length, ‘65 inch; breadth, :83 inch. Length of aperture, :25 inch. 
Locality. Petane. A small variety is also found at Wanganui. 
Clathurella dictyota. Pl. xviii., fig. 8. 
Shell minute, elongato-fusiform. Whorls 6, the first two embryonic ; 
the others slightly angled and cancellated. Longitudinal ribs narrow and 
distant, about eleven in a whorl. Spire whorls with three strong distant 
spiral ribs, the interstices finely spirally striated ; body whorl with about 9 
spiral ribs, the posterior three larger, and alternating with a small rib 
between each, as well as the spiral striæ. Aperture oval, nearly half the 
length of the shell; posterior sinus broad and shallow; anterior canal 
moderate. 
Length, :28 inch; breadth, 1 inch. Aperture, 11 inch. 
Locality. Wanganui and Petane. 
This species approaches C. oxyclathrus, Martens, but the spiral ribs are 
fewer and further apart. i 
Clathurella abnormis, 
Shell minute, mitriform, the spire produced and acute. Whorls 61, the 
first 14 embryonic, polished; the others angled, strongly longitudinally 
costate and delicately spirally lined. There are eleven longitudinal ribs on 
a whorl, which are crossed by three or four spiral threads in front of the 
angle, none behind it. On the body whorl, the spiral threads in front of 
the angle are about 12, some of which are stronger than others. Aperture 
linear ; the right lip rather thick but not grooved; a posterior shallow sinus 
above the angle ; columella smooth. 
Length, -2 inch ; breadth, :08 inch. Aperture, -09 inch. 
Locality. Petane. 
