XXiv. 
CLASS AMPHINEURA. 
ORDER POLYPLACOPHORA. 
In this Order the recent monograph by Pilsbry has been followed in 
the main. 
SUB-ORDER EOPLACOPHORA. 
Lepidopleuride. 
Lepidopleurus, Risso, 1826. 
(type L. cajetanus, Poli.) 
L. cancellatus, Sow., 1839. 
L. seabridus, Jeff., 1880. 
L. onyx, Spengler,1797 (= cinereus, 
auct., non L.) 
Hanleya, Gray, 1857. 
(type) H. Hanleyi, Bean. 
SUB-ORDER MESOPLACOPHORA. 
Ischnochitonide. 
Tonicella, Carpenter, 1873. 
(type) T. marmorea, Fabr., 1780. 
T. ruber, Z. 
Callochiton, Gray, 1847. 
(type) C. levis, Mont., 1803. 
Trachydermon, Carpenter, 1863. 
(example) T. cinereus, Z. ( =warginatus, auct.) 
T. albus, L. 
Acanthochitide. 
Acanthochites, Risso, 1826. 
According to Mr, Pilsbry the first two species are probably our 
British forms. 
A. discrepans, Brown, 1845. 
A. fascicularis, L. 
