SPECIES OF THE SYSTEMA. 
C2 Hob TON, 
FIvE more species of Chiton are present in the twelfth than in 
the tenth edition,—to wit, fascicularis, squamosus, ruber, albus, 
and cinereus; a marked improvement, likewise, may be dis- 
cerned in the descriptions of twberculatus and aculeatus, to which 
the terminal paragraphs were added. ‘The term “corpus” is 
used for the leathery rim in which the valves are imbedded: 
eyen thus early the value of the margin for divisional purposes 
was appreciated. The localities authenticated by Zoega, Bran- 
der and Konig may be trusted to. 
Chitown hisp(dus. 
Of the sole descriptive characteristics ‘‘ sexvalvi, striata,” by 
which this shell is sought to be defined, the former is merely 
accidental, the latter common to the majority of the genus. 
Taking the name itself “ hispidus”’ into account, and applying 
it to the margin solely, a third and far from insignificant limita- 
tion may be obtained; and as the other three original species 
are all named from the character of rim, the fourth may fairly 
be presumed to have been so likewise. Schréter, however, 
whose Chiton hispidus (‘ Einleitung in die Conchylien Kentniss,’ 
vol. i. p. 493, pl. 9, f. 18) seems a very bold and rather unfor- 
tunate attempt at identification, appears to infer that the term 
was applied from the prickly nature of its striz. 
No light is obtained from the manuscripts or collection of 
our author, who did not possess the shell, which, as a Linnean 
species, had better be rejected from our catalogues. 
