ISCHNOCHITONID AE 3 2 3 



I to 1V2 inches in length, rather oval in shape. Color variable: com- 

 monly yellowish with dark reddish brown streaks and maculations. Central 

 areas with strong, longitudinal ribs and smaller, lower cross ridges which 

 give a netted appearance. Jugal area V-shaped and with 5 to 6 smooth longi- 

 tudinal ribs. Lateral areas raised, smoothish and with a few prominent warts. 

 Anterior valves with 30 or more radial rows of warts which are largest 

 near the girdle. Interior whitish, or rarely tinged with pink. Girdle with al- 

 ternating yellowish and reddish bands; covered with tiny, low, smooth, split- 

 pea scales. Very abundant just offshore, especially in the northern part of 

 its range. 



Iscknochiton calif orniensis Berry Trellised Chiton 



Southern California to Lower California. 



I to 1% inches in length, oval to oblong, heavily sculptured. Color a 

 dull-greenish with yellowish splotches and with a dark-brown area on the 

 top of each valve. Central area with longitudinal and cross ribs which give a 

 strong netted appearance. Lateral areas raised and with 4 rows of prominent 

 beads. Posterior edge of valves serrated with about 20 small tooth-shaped 

 beads. Anterior valve with 20 to 27 strongly granular ribs. Girdle closely 

 packed with convex, tiny, split-pea scales. Moderately common and for- 

 merly thought to be /. clathratus Reeve which, however, is only from the 

 Panamic Province to the south. 



Ischnochiton cooperi Pilsbry Cooper's Chiton 



Southern California. 



I to 1% inches in length, rather oval in shape. Color olive-green to 

 olive-brown and clouded with light-blue. Central area with closely packed, 

 sharp, longitudinal ribs which are finely striated. Jugal area with the same 

 type of ribs and with its anterior end having about 10 notches. Lateral areas 

 raised and with 4 to 8 irregular rows of prominent, rounded warts. 

 Interior of valves bluish. Girdle covered with tiny, flat, striated, split-pea 

 scales. Uncommon. 



Ischnochiton palmulatiis Pilsbry Big-end Chiton 



Southern California. 



% inch in length, oblong and with the posterior valve massive and 

 greatly swollen. Color of valves yellowish brown to light grayish green 

 with dark blackish green in the areas just above the girdle. Central areas 

 carinate at the top, with 20 to 30 strong, rounded, longitudinal ribs. Lateral 



