326 MOLLUSCA. 
CHITON ASPERRIMUS, (Couthouy MS.) 
T. minuta, elongato-ovata, convexiuscula, subcarinata, fusco-olivacea ; 
areis lateralibus conspicuts, papillis sparsis columne-formibus obsitis ; 
areis centralibus papilhs similibus longitudinaliter dispositis ornatis : 
ligamentum coriaceum, pubescens. 
ANIMAL with the head, foot, and margin pale yellow ; duplication of 
the mantle above the branchiew of a deeper yellow; branchie pale 
orange ; buccal mass broad and fleshy, prolonged into lobes inferiorly. 
Sue. elongated-oval, narrowed anteriorly, moderately convex, sub- 
carinate, brownish-olive along the back, with a lilac bloom at the 
margin; posterior valves semilunar; lateral areas large, extending 
quite to the anterior edge of the valves, ornamented with irregularly 
scattered, cylindrical eminences, which are easily detached, leaving a 
scar; the central areas have thickset, longitudinal ranges of similar 
eminences. Margin coriaceous, covered with short and scattered 
sete. 
Length one inch; breadth two-fifths of an inch. 
Obtained at Ilha do Pai, at the entrance of the harbour of Rio 
Janeiro. [3J. P. c.] 
The peculiar character of the granulations, like little cylindrical 
pedestals, is alone enough to identify the species. 
Figures 418, 418 a, dorsal and ventral views of the shell and animal ; 
418 d, details of sculpture, enlarged. 
Cuivron CASTANEUS, (Couthouy MS.) 
T. minuta, elongato-ovata, subcarinata, castanea, liners incrementi por- 
cata, minutissime quincuncialiter punctata; margo angustus coria- 
ceus, pubescens, fasciculis setarum viginti-sex instructus. 
AnimaL with the under side of the margin pale brick-red ; foot nar- 
