TONICIA. 207 



teeth sharper, very deeply pectinated. Eaves wide ; sinus 

 minutely denticulated. This species and the following, with 

 truncata, are intermediate between Tonicia and Acanthopleura ; but 

 they agree with this genus in the porcellanous texture, deep slits, 

 angular denticulated sinus and pectinated teeth. The slight lanuga- 

 tion of the girdle appears to be a secondary character. 



T. NIGROPUNCTATA Carpenter. Unfigured. 



Shell small, rather elongated, elegantly clouded olivaceous and 

 brown ; moderately arched, the dorsal ridge obtuse. Lateral areas 

 moderately defined, ornamented with radiating and longitudinal 

 wrinkles irregularly decussating, with black dots scattered between 

 them. Central areas having subparallel, subdecussating, scarcely 

 regular ribs, obsolete at the jugum. Mucro posterior, elevated. 



Interior having 8-10 slits in the anterior, 1 in the central, 12-14 

 in the posterior valve ; teeth in the posterior valve solid, sloping, 

 short ; sinus broad, denticulate. Girdle copiously clothed with hair- 

 like scales. Length 12, breadth 6'2, alt. 1-7 mill. (Qpr.) 



Tahiti. (Pease.) 



Acanthopleura nigropunctata CPU., P. Z. S. 1865, p. 511. PEASE, 

 Amer. Journ. Conch, vii, p. 194. Tonicia nigropunctata CPU., MS. 



This species is most closely allied to T. suezensis, but the latter 

 has the valves more beaked and curved, and the central rugae per- 

 pendicular to the diagonal lines, while in this they are nearly 

 parallel to the dorsal ridge. ( Opr.} 



T. FORTILIRATA Reeve. PI. 40, figs. 3, 4 (enlarged.) 



Shell ovate ; valves somewhat beaked in the middle ; posterior 

 valve umbonated, blunt; lateral areas rather concave, granulated 

 anteriorly; central areas strongly arcuately ridged. Yellowish 

 variegated with green, stained with red in the middle. Ligament 

 horny. (Reeve.) 



Raines Island, Torres Sts. (Ince) ; Port Darwin, 8-10 fms. sand 

 and mud (Coppinger.) 



Chiton fortiliratus"Rvv., Conch. Icon., t. 18, f. 112. C. (Tonicia) 

 fortiliratus SMITH, Zool, ' Alert ' p. 84. 



Carpenter writes of the type : Anterior valve having 6, central 

 valves 1, posterior valve 13 slits ; teeth short, numerous, very sharply 

 pectinate ; short at the hinder end but gradually becoming a little 

 longer. Eaves short, slightly rugose, not spongy ; sinus with about 

 20 teeth, rather broad, flat. Interior whitish. Outside ashy 



