44 Art. 6. — M. Yokoyania: 



Family Cancellariidae. 



Genus Canceilaria, Lamarck. 



28. Canceilaria spengleriana, Deshayes. 



Pl. II. Figs. 2, 3. 



Canceilaria spengleriana. Sowerby, Thes. Conch., vol. TL, p. 439, pl. 93, fig. 29. Dünker, 

 Index Moll. Mar. Jap., p. 103. Tokunaga, Foss. Env. Tokyo, p. 11, pl. I, fig. 15. 



This is a shell which is very frequently met with living in 

 Central and Western Japan. The form is in general suboval with 

 a short but pointed spire. The whorls number about eight, of 

 which the first two are embryonal and smooth; the others are 

 angulatecl, with the surface above the angle somewhat sloping or 

 nearly horizontal, and with the surface below the same nearly 

 perpendicular, so that the angle may be obtuse or sometimes 

 nearly right-angled. The sculpture consists of rounded longi- 

 tudinal ribs and tine spiral grooves which latter make the surface 

 between them look like broad flattened transverse riblets. The 

 number of longitudinal ribs varies between ten and fifteen, so that 

 in some specimens they are closer than in others. They are more 

 or less tuberculated at the angle, the tubercles often being sharp 

 and somewhat spiny. Below the angle and especially in the 

 body-whorl, their crossing points with the spiral riblets show a 

 tendency to elevate themselves into tubercles. The oblique folds 

 of the columella are normally three in number, but there is often 

 a fourth one developed between the upper two, though somewhat 

 smaller. The lip outside of the folds is more or less tubercular, 

 with rounded and elongated elevations, Sowekby's description, 

 that the columella is granulated probably pointing to this character. 

 The outer lip is denticulate at margin with many distant spiral 

 threads within. Rather frequent. 



Fossil occurrence. — Yokosuka Zone (Otsu); Xaganuma Zone 

 (Naganuma); Upper Musashino of Musashi, Shimosa and Kazusa. 



Living. — Central and Western Japan; Philippines; Australia. 



