156 CHITON. 



valve 13 slits. Eaves narrow, short, somewhat spongy ; sinus and 

 slit-rays hardly porous. Teeth pectinated. 



Girdle alternately light green and whitish, covered with smooth 

 convex-flattened scales. 



Length 60, breadth 32 mill. 



Length 45, breadth 28 mill. 



Cuba, Jamaica, St. Thomas and St. Croix, West Indies. 



Chiton squamosus LINNE, Mus. Ulricas, p. 465 (1764). Chiton 

 squamosus L., Syst. Nat. xii, p. 1107. SPENGLER Skrivter af Natur- 

 historie-Selskabet iv, p. 67, t. 6, f. 2 (1797). HANLEY, Shells of 

 Linnaeus, p. 15 (1855). NOT Chiton squamosus of authors. Chiton 

 tigris SPENGLER, L c., p. 68 (a depressed form ; see Chemn. viii, f. 

 792, 793). Chiton scaber variegatus CHEMN. Abh., p. 31, t. 1, f. 3 ; 

 Conchyl. Cab. viii, p. 276, t. 94, f. 792, 793. Chiton fasciatus WOOD, 

 Gen. Conch., 1815, p. 10, t. 1, f. 4, 5 (excl. syn.). SOWB., Conch. 

 Illustr., f. 153. SHUTTLW., Bern. Mittheil. 1853, p. 74. Chiton 

 chemnitzii PFR., Krit. Register zu Mart. u. Ghemu., p. 78, 1840. 

 Chiton marmoreus REEVE, Conch. Icon., t. 12, f. 64 (not of Chemn. 

 nor Fabr.) 



This species is colored in much the same fashion as some striped 

 forms of C. marmoratus, and it also agrees with that species in the 

 smooth central areas; but the dullness of the surface and the 

 minutely beaded lateral areas at once separate the two forms. 

 Specimens vary greatly in degree of elevation and consequently in 

 the size of the angle of divergence. 



Linnaeus gives an unusually full description of this species, amply 

 sufficient to distinguish it from the shell which Born, Gmelin, and 

 later authors confused with it. Spengler correctly identified it in his 

 monograph of 1797, and gave a most excellent figure and a good 

 description. Hanley found Linnaeus' original type still preserved in 

 his collection, but the C. squamosus of authors is not present there. 

 It should be noted that Linnaeus' specific names of Chitons were 

 intended to be descriptive of the girdle, not the valves. 



C. VIRIDIS Spengler. PI. 33, figs. 64, 65, 66, 67. 



Shell oval, moderately elevated, carinated, side-slopes slightly con- 

 vex. Color varying from gray-white to olive, irregularly marked 

 on the central areas or on the ridge with blackish ; sometimes black- 

 brown all over. 



