DBOHVO4 HI i' 



Chifnn /><><( in, it //.< S,\\ I ;.. M a-. , ,f N ill . I I i~f ., .lime. |S-lU. p. : ' 

 t. 1C., t'. :i ; Conch. Illustr. ('. 1 1C,. |;, ., \ , . ( ',,, ,,.),. I 



1 83, ' ' /-'hnn.'hitiiii i pectinatu* SIM n u.\\ ., Hem. Mitthdl. I 



|t. 77. I.tf'hnniilii.r }irrtiu'lfu.i CPB., M>. Chiton ncnti/i, 



KI:I;\I:, Condi. Icon. t. *, f. Mt.--Chitnn miill'u-n*tuhi# ('. \\. Ah., 



Proo, r..st. Boo, N. II. ii, |. 8, ! 



LVadily known from other \Ve>l India ( 'hitons liv its dong 

 r.inn, speckled and mottled coloring, SUM! especially \>\- the 

 peculiar ^irdlo. The larirf scales are distinctly but finely Mriated. 

 The grOUnd-Oolor of the girdle is pale bufl', with patches of olive- 

 ii'reen. The larLie scales are mingled white and buff on the liirlit 

 tracts, and are a dark blue-green on the dark patches. 



Reeve's C. acutiliratm (fig. 30) is a typical pcH'n,<ihi.<. \ have 

 not seen the Ch.multicostatus of C. B. Ad., described from .Iain; 

 and the description is too meager to permit certainty in referring it 

 here. 



Subgenus IV. HETEROZONA Carpenter, 1878. 



Heterozona CPR. (Table of Regular Chitons, 1 873), DALL, Proc. 

 T. S. Nat. Mus. 1878, p. 331. Type H. cariosa Cpr. MS. 



Shell like normal Ischnochiton ; girdle bearing small scales with 

 large striated scales intermingled. 



The girdle is that of Ischnoplax, but the shell is not elongated, 

 and the umbo of the posterior valve is median, not posterior. The 

 arrangement of scales normal in this section is the same as a patho- 

 logic condition sometimes met with in individuals of species 

 normally having regular and equal scales, but in which the girdle 

 has been injured; the injury being repaired with scales much 

 smaller than those upon the healthy portions of the girdle. 



I. CARIOSUS Carpenter, n. sp. PI. 24, figs. 20, 21, *2'2. 



Shell oblong, rather elevated, the valves broadly arched and 

 rounded dorsally. Color, soiled yellowish, unieolored or with 

 indistinct brown spots. 



The lateral areas are raised, and sculptured with a var\ in- num- 

 ber (about 7) of radial ribs, which are irregular, often splitting. 

 and very unevenly granose. Central areas finely granulated upon 

 the dorsal ridge, the granulation giving place on the side-slopes to 

 a rather strong but fine corrugation ; the wrinkles longitudinal, 

 but converging forward toward the middle: and minutely irregular 

 5 



