200 SEMICASSIS. 



shoulder, and several better-marked lineations near the anterior 

 extremity. Columella twisted medially, furnished with a number 

 of small, iri'egular plications. 



It is, apparently, the precursor of the living *S'. 7iivea, Brazier, 

 of the Australian seas. 



Dimensions. — Length 29 mm.; breadth 20 mm.; length of 

 aperture and canal 21 -5 mm. 



Form, and Loc. — Miocene : Muddy Creek, Yictoria. 



G. 5506. An example of the adult. Purchased. 



Subgenus CASMARIA, H. and A. Adams. 



[Gen. Eec. Moll. vol. i. 1853, p. 216.] 



Whorls almost smooth, or plicated longitudinally; outer margin' 

 smooth, or only slightly crenulated ; columella smooth. 

 Type. — Biiccinum vibex, LinniBus. 



Semicassis (Casmaria) pyrum, Lamarck (sp.). 



1822. Cassis pyrum, Lamarck, Anira. sans Vert. t. vii. p. 226. 



1844. Cassis pyrum, Lamarck, id. 2nd ed. t x. p. 33. 



1848. Cassis pyrum, Eeeve, Conch. Icon vol. v. pi. xi. figs. 29a-c. 



1873. Cassis pirum, Von Martens, List Moll. N.Z. p. 24. 



1873. Cassis pyrum, Hutton, Cat. Marine Moll. N.Z. p 20. 



1873. Cassis pyrum, Hutton, Cat. Tert. Moll. N.Z. p. 8. 



1873. Cassis striatus, Hutton, id. p. 8. 



1880. Cassis pyrum, Hutton, Man. N.Z. Moll. p. 66. 



1885. Cassis {Semicassis) achatina, Lamarck, var. pyrum, Tryon, Manual of 



Conchology, vol. vii. p. 278, pi. viii. figs. ft6-8 ; pi. ix. fig. 7. 



1893. Cassis pyrum, Hutton, Linn. Soc. N.S.W., Macleay Mem. Vol. p. 53. 



Shell ovate, ventricose ; whorls obscurely angulate posteriorly, 

 nodose on the angulations ; whorls of the spire irregularly spirally 

 sulcate, body-whorl of the adult spirally sulcate near the suture 

 and towards the anterior portion only, the middle being smooth; 

 aperture dilated; columella smooth, having a large plait anteriorly; 

 outer margin reflected, smooth. 



Dimensions. — Length 42 mm.; breadth 31mm.; length of 

 aperture and canal 29 mm. 



Form, and Loc. — Pliocene : "Wanganui, New Zealand. 



G. 9536. An example of the adult. Sir James Hector Coll. 



