Vol. XI] BERRY— FOSSIL CHITONS 455 



Genus Katharina Gray, 1847 



17. Katharina tunicata (Wood, 1815) 



(Plate VI, figs. 1-6) 



1815. Chiton tunicatus Wood, Gen. Conch., p. 11, pi. 2, f. 1. 



1828. Chiton tunicatus Wood, Index Test., p. 2, Chiton, pi. 1. 

 f. 10. 



1847. Katharina tunicata Gray, Proc. Zool. Soc. Lond., 1847, 

 p. 69. 



1893. Katharina tunicata Pilsbry, Man. Conch., (1), v. 15, p. 

 41, pi. 1, f. 1-11. 



1919. Katherina tunicata Chace, Nautilus, v. 30, p. 71 (re- 

 corded from Pleistocene of Deadman Id., Cal.). 



Diagnosis: Valves massive ; tegmentum greatly restricted, 

 more or less flask-shaped in the median valves, with an elon- 

 gate, neck-like projection in front jutting into the sinus; areas 

 not well delimited, except for the slightly elevated jugal tract 

 extending back from the anterior process ; sculpture obsolete 

 except for the rather strong lines of growth and about 8 weak, 

 radial ribs on the head valve ; insertion plates in valves ii-viii 

 coalescent with the immensely developed and flaring sutural 

 laminae, in valve i long with strong grooves radiating to short 

 slits at the margin, in valve viii directed abruptly forward from 

 the blunt, posteriorly projected mucro; articulamentum of tail 

 valve with a distinct posterior sinus ; eaves and sinus spongy : 

 slits 8+, 1-1, 1-1. 



Recorded Range: 



Pliocene: Santa Barbara Formation — Deadman Island, 

 San Pedro, California ( !). 



Pleistocene: Formation doubtful — Deadman Island, San 

 Pedro, California (Chace, !). 



Indian Middens: Near Cypress Point, Monterey County. 

 California ( !). 



Lhnng: Kamtschatka and Aleutian Islands to Santa 

 Catalina Island, California; between tides, but occasionally to 

 20 fathoms (Pilsbry). 



