ON A NEW TASMANIAN CHITON. 

 By W. G. Tor-, LL.D. 

 Communicated by W. L. May. 



(Read 15th April, 1912.) 



CALLOCHTTON MAYI, SP. NOV. 



General Appeara7ice. — Shell elliptical, strongly elevated, 

 and carinated. Side slopes slightly curved, and steep. 

 Colour : Rusty red, mottled virith white. 



Afiteriot Valve. — Perfectly smooth, several concentric 

 grooves which are probably growth lines. Microscopically 

 granulous and arenaceous. Teeth : 16 slits ; teeth and slits 

 irregularly spaced. 



Posterior Valves.— M-Ucro Median, prominent. Dorsal 

 area microscopically striate. Pleural areas have five or six 

 deep longitudinal grooves. The lateral area seems perfectly 

 smooth, but is microscopically granulated. Twelve slits. 



Median Valves. — Dorsal area wedge shaped, micro- 

 scopically longitudinally striated, slightly beaked. Pleural 

 area : Eit^ht deep longitudinal sulci, separated by sharp 

 edged ribs, cross the valve, except where cut off by 

 the dorsal area. Lateral areas, distinctly and remark- 

 ably raised, with a rounded rib on each side, the anterior 

 one being the most conspicuous ; and several concentric 

 growth lines. The whole surface microscopically granu- 

 lated. Three teeth on each sid?, more or less thickened 

 at the sides, or "propped." 



Girdle. — Densely covered with microscopically dia- 

 mond-shaped scales, which are only the points of long 

 flattened, closely appressed corneous bodies. — This helps to 

 fix the genus of this shell. 



Measurement. — Length 15, breadth 8 m.m. 



