ACANTHOPLEURA. 221 



Nuttallina scabra Rve. bears a slight resemblance to this species, 

 but it is differently sculptured, has smooth teeth and less spiny 

 girdle. The tail-plate of A. spinosa is like that of Katharina tun- 

 icata, on account of the long, vertical teeth. 



A. SPINIGER Sowerby. PL 48. 



Shell oblong-oval, moderately elevated or depressed, lusterless, 

 microscopically granulated and having a more or less developed 

 sculpture of granules which either stand distinct or coalesce to form 

 concentric wrinkles. Color dead-leaf brown or soiled whitish where 

 eroded ; generally black at dorsal ridge and sides of each valve or 

 some of the valves ; on each side of the black dorsal stripe there is 

 generally a streak of green. Girdle broad, black or alternated with 

 whitish.' The valves are rounded at the ends, somewhat beaded ; 

 lateral areas but little raised, granulated or wrinkled, the forward 

 part crowded with microscopic bead-like amber eyes. Central areas 

 having wrinkles of growth and sometimes low, scattered granules, 

 more numerous and stronger at the sides. Posterior valve having 

 the mucro somewhat behind the center. 



Interior of a purple-brown color, darker in front of the callus of the 

 valve and on the sutural plates, lighter behind the callus of the 

 valve. Sutural-plates broad, extending laterally much beyond the 

 rounded ends of the tegmentum. Sinus rounded, sometimes black- 

 edged. Anterior valve having 9-11, central valves 1, posterior 

 valve about 7 (6-10) slits ; teeth pectinated, those of the tail-valve 

 much longer than the eaves. 



Girdle broad, closely covered with calcareous black or buff spines 



Length 70, breadth 43 mill. 



Fiji Is. ; Viti Is.; New Caledonia (A. Garrett in Phil. Acad. Coll.) ; 

 Cagayan, Isl. of Mindanao, and Siquijor, Philippine Is. (Cuming) ; 

 New Guinea, New Ireland, and Tonga-Tabu, (Quoy and Gaimard) ; 

 Port Essington (Jukes) ; Port Molle and Clairmont and Bird Island 

 (Coppinger); Lat. 10 36' S., Long. 141, 55' E., Albany Island, 

 Cape York, North Australia, in 6 fms. (Challenger.) 



? Chiton aculeatus LINNE, Syst. Nat. x, p. 667 (founded upon 

 Rumphius Amboinische Rariteitkamer, pi. 10, fig. 4.) 



Chiton nicobaricus aculeatus, CHEMN. Conch. Cab. x, p. 375, f. 

 1692. Chiton aculeatus SPENGLER, Naturhist. Selskabet, iv, p. 78. 

 Chiton aculeatus QUOY & GAIMARD, Voy. de T Astrolabe, Zool. 

 iii, p. 373 ; atlas, t. 74, f. 1-5 (1834), 



