ASPIDOBRANCHIA. CHITONID. 227 
and the veil of the mouth; its anterior aspect receives from 
the veil many small branches of nerves: two ganglia situated 
on each side below the brain ; each of them sends off two nerves, 
which, joining together, form the anterior part of the annular 
circle of nerves: the two posterior ganglia each receives three 
nerves, and are connected to each other by an intermediate 
nervous branch, which forms the posterior part of the nervous 
circle, and renders it perfect: these nervous branches, which join 
the ganglia behind, most probably rise out of the viscera and 
the muscles of the foot. Although my friend Professor Cuvier 
and myself have exerted all our endeavours to trace the origin 
of these nerves, we have been unsuccessful ; owing to the exotic 
specimens we dissected being so much hardened by the spirit 
in which they were preserved, as completely to baffle us. I 
have however been enabled to trace their origin a very little 
more than Baron Cuvier. 
Synopsis Generum. 
Membrana lateralis squamosa .... 104. LEPIDOPLEURUS. 
Membrana lateralis spinularum fasci- 
SM MIGETUCEA, 2 re. 105. ACANTHOCHATES. 
Membrana lateralis tomentosa, _his- 
pida aut rugulosa ............ 106. Cuiton. 
Genus 104. LEPIDOPLEURUS. 
Testa membrana laterali squamosa. 
Shell with its lateral membrane covered with scales. 
1. LEPIDOPLEURUS ALBUS. 
L. testa alba, dorso tuberculis minutis elevatis sculpta ; mem- 
brana laterali squamis rugulosis sculpta. 
Chiton albus, Linn. Syst. Naé. xii. 1107.no. 8; Chem. Conch. 
8. t. xevi. f. 817; Pult. Cat. Dorset. 25. t.1.f. 5; Mont. 
Test. Brit.4; M.&R. Trans. Linn. Soc. viii. 22. t. 1. f. 4; 
Flem, Edinb. Encycel. vii. ; Dill. Desc. Cat.11; Turt. Conch. 
Dict. 35. 
Habitat in mari Europzeano vulgaris, thalassophytis et conchis 
adherens. Long. 2 unc. 
