POLYPLACOPHORA. 99 



This species differs from Ch. janeirensis in having the lateral ribs 

 bifid, and the sculpture generally more minute. (Sowb.) 



6. New Caledonian species. 

 CHITON OBSCURELLUS Souverbie. PI. 10, figs. 8, 9. 



Shell ovate-oblong, narrower in front, the back carinated ; ante- 

 rior valve radially delicately tuberculate , posterior valve scarcely 

 umbonated, the beak subapical. Anterior margins of the lateral 

 areas a little raised. Entire surface of all valves most minutely, 

 densely granose-scaly. Color brown ferruginous, luster less, with a line 

 articulated with black and white in front of the diagonal border of each 

 lateral area. Girdle most minutely scaly. 



Length 5, breadth 3* mill. (S. & If.) 



Island of Art, New Caledonian Archipelago. 



Chiton obscurellus Souv., Journal de Conchyl. 1866, p. 251, t. 9, 

 f. 4. 



The generic position of this species is quite unknown to me. It 

 was described from a single specimen, now in the Bordeaux 

 Museum. 



CHITON SUBASSIMILIS Souverbie. PI. 10, figs. 1, 2. 



Shell ovate-oblong, the back carinated. End valves and lateral 

 areas sculptured with numerous radii, more or less anastomosing and 

 eubgrauulose, being decussated by growth-lines. Central areas lon- 

 gitudinally traversed by well-impressed, subflexuous, suboblique 

 grooves, deeper and more widely spaced toward the outer edges, 

 becoming obsolete toward the median carina, which is smooth ; 

 visibly crossed by fine growth-striae. Entire surface extremely finely 

 shagreened when seen under a lens. Color dark green, with numer- 

 ous longitudinal white lines on the central areas, and small spots of 

 the same color on the end valves. Girdle scaly-coriaceous, with large 

 alternate blotches of olivaceous and ashen. 



Length 20, breadth 9 mill., excluding girdle. (Souv.) 



Island of Art, New Caledonian Archipelago. 



Chiton subassimilis Souv., Journ. de Conch. 1866, p. 254, t. 9, f. 2. 



Described from a single example, which is in the Bordeaux 

 Museum. Souverbie compares it to assimilis Reeve. 



CHITON TUBERCULOSUS Souverbie. PI. 10, figs. 5, 6. 



Shell ovate-oblong, the back obtusely carinated; gray ish-buff, with 

 a dull white spot on each side of the carina. End valves margined 



