﻿182 Transactions. — Zoology. 



ACANTHOCH^TES OVATUS. Sp. IIOV. 



Ovate, attenuated in front ; margin spiny, with nine small bundles along 

 each side ; valves flatly triangular, sub-carinate, posterior valve very narrow, 

 apex re-curved ; posterior margins of the anteiior plate sloping backwards into 

 a point, those of the posterior plates nearly straight ; anterior valve with ten, 

 and lateral areas with two on each side, radiating nodulose ridges ; median 

 areas with slightly waved longitudinal ridges ; dorsal line smooth. 



Length, -6 inch ; breadth, -5 inch. 



Colour. — Mantle pale reddish brown; spines white; valves greenishi 

 white ; yellowish on the dorsal line. 



Several specimens in the Colonial Mtiseum, locality not stated. 



ACANTHOCHiETES HoOKERI. 



AcanthocJicetes Hooheri, Gray, " Diefi". N.Z.," Yol. II., p. 262. 



Oblong ; mantle spiny with nine large radiating tufts of spines on each 

 side ; valves flatly triangular, sub-carinate ; posterior margins slightly convex, 

 with an obtuse central point ; terminal and lateral areas granulose ; median 

 areas smooth ; lateral areas very large. 



Length, 1 inch ; breadth, "4 inch. 



Colour. — Mantle brown; spines pale green; valves generally greyish 

 black, more or less varied with yellowish ; often yellowish or reddish on the 

 dorsal line; occasionally greenish. 



Several specimens in the Colonial Museum, Wellington Harbour; it is 

 not uncommon on stones below low water mark. 



Genus Katharina. Gray. 



Yalves partly hidden on each side by an expansion of the mantle, sides 

 smooth ; uncovered portions of the valves as broad as long. 

 West Coast of South America. 



Katharina violacea. 



Cliiton violaceus, Quoy and Gaim., " Voy. Astrol., " Yol. IIL, p. 403. 

 Chiton violaceus, Desh., " Anim. sans Yert.," Yol. YII., p. 519. Acantho- 

 choites violaceus, Gray, " Diefl". N.Z.," Yol. II., p. 246. 



Elongated oval ; margin smooth ; valves rounded, depressed ; posterior 

 margins waved ; anterior valve granulose, six-sided, separated by flat nodulose 

 lines ; posterior valve small, rounded, granulose ; lateral areas small granulose j 

 dorsal line smooth, with several irregular rows of longitudinal punctures on 

 each side ; sides granulose ; nine bundles of spines on each side. 



Length, 1'5 inch; breadth, '65 inch. 



Colour. — Mantle brown, valves violet. 



In rock basins near low water mai-k. Cook Straits. 



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