84 ISCHNOCHITON. 



Chiton fulgetrum EEEVE, Conch. Icon. t. xiii, f. 71, March, 1847. 

 f Trachyradsia fulgetrum CPE., MS. p. 24. ? Chiton dentatus, 

 SPENGLER, Skrivter af Naturhistorie-Selskabet, iv, p. 88, t. 6, f. 16, 

 Kiobenhavn, 1797. 



Carpenter writes as follows of the type specimen, unique in the 

 Cuming Collection : The mucro is prominent and median, the slope 

 behind it very concave. The interior is vivid rose color. 



The insertion plate of the front valve has 20 slits, median valves 

 4 to 5, and posterior valve 18 slits. Sinus small, imperfect in each 

 valve, but probably as shown in fig. 81. Eaves small. 



Girdle thin, wide, ornamented with small, scarcely imbricating, 

 slightly elongated, very close, deciduous scales. 



Length 63, breadth 38 mill.; divergence 103. 



The scales are extremely minute deciduous, crowded into an 

 irregular spongy mass, and when seen separately are not like a flat 

 spine as in Callochiton, but somewhat rectangular and scarcely 

 elongate. They have perished over most of the specimen, although 

 that is in fine condition. It appears to have been tessellated with 

 white over the chestnut surface but most of the specimen is now of 

 a light horn color. The radsioid character of the valves and the 

 brilliant rose interior makes this specimen very like castaneus but it 

 is known outside by the obsolete riblets formed by slight depressions 

 co-ordinate with the slits inside. Even these do not appear in the 

 younger part of the shell. The color markings are probably vari- 

 able. It is probably from S. Africa. (Cpr.) 



I. ALEUTICUS Dall. Unfigured. 



Shell small, rufous-ashen, oblong, vaulted, the jugum very acute ; 

 mucro submedian ; apices prominent ; lateral areas inconspicuous, 

 entire surface minutely reticulated in quincuncial pattern. 



Interior: anterior valve with 16, central with 2, posterior with 

 11 slits; teeth small, very spongy, widely separated ; eaves spongy, 

 sinus small. Girdle beset with minute scales. (Dall.) 



Length 6, width 3 mill. 



Kyska Harbor, Kyska Id. ; Constantine and Kiriloff Harbors, 

 Amchitka Id., and Nazan Bay, Atka, in the western Aleutians, at 

 low-water mark, under stones on the beach. 



Trachyradsia aleutica DALL, Proc. U. S. Nat. Mus. p. 1, Jan., 

 1878 and t. c., p. 323. 



