36 AMPHINEURA. [Polyplacophora. 



the centre, the whole minutely wrinkled. Posterior valve with a few 

 concentric ridges near the margin, surface wrinkled as on the other 

 valves, mucro central, low, posterior slope strongly convex. Girdle 

 with small, rounded, smooth, and imbricating scales. Colour dark 

 brown, somewhat lighter on the central and lateral areas ; girdle 

 darker, almost black. Interior light brown ; anterior valve with 

 11 slits and intermediate valves with 1 slit on each side, posterior 

 valve with a low insertion plate and 12 slits ; teeth thick and blunt, 

 with 1 or 2 grooves outside ; sinus microscopically denticulate ; sutural 

 laminae moderately high and broadly rounded. 



Length, 9 mm. ; breadth, 4-5 mm. Divergence, 100. 



Type in my collection. 



Hob. Bluff, South Island ; type (Dr. Torr). 



Remark. This species stands nearest to C. Sinclairi, but is easily 

 distinguished by its almost total smoothness and the microscopic 

 wrinkles. 



6. Group of Chiton canaliculatus. 



Central areas with stout longitudinal ribs and comparatively deep 

 grooves. 



5. Chiton sreus, Reeve, 1847. Plate 2, fig. 15 ; Plate 4, fig. 9. 



Chiton wre,us, Reeve, Conch. Icon., pi. 7, f. 36 ; Man. Conch. (1), siv, 179, 

 pi. 36, f. 96, 97 ; Ereb. & Ter., pi. 1, f. 9 ; J. Mai., xii, 70 ; T.N.Z.I., 

 xl, 376. 



Shell oblong-ovate, angularly raised in the middle, valves rudely 

 impressly striated ; colour greenish, red, or yellowish-white. Anterior 

 valve with 20-30 but slightly nodulose radiate riblets, crossed by 

 fine concentric lines of growth. Intermediate valves with the jugum 

 sharply angled, smooth, microscopically shagreened, the central areas 

 with about 20 furrows on each side, not deep, continuing until they are 

 rubbed off in the middle ; lateral areas slightly raised, with 3 to 4 

 divaricating riblets, broken up by the concentric ruga? of growth, 

 smoothish ; crenate at the sutures. Posterior valve with 15 to 20 

 radiate riblets extending from the mucro to the posterior margin, 

 shorter ones between them ; riblets cut up into distinct oval granules 

 by concentric lines of growth ; central area longitudinally furrowed ; 

 mucro in front of the middle, pointed, posterior slope concave. Girdle 

 with imbricating roundish and rather large scales, the rows on the 

 inner and outer margins have smaller scales ; they are microscopically 

 finely striate. Colour dull green, clouded with black on the sides, 

 sometimes brick-red, with or without faint black or brown patches 

 on the sides of the central valves ; rarely yellowish-white, sometimes 

 beautifully marked with greenish zigzag bands, especially upon the 

 lateral areas ; girdle mostly irregularly banded with white ; quite 

 white specimens have the girdle dark brown. Interior light blue, with 

 the sutural lamina' white; anterior valve witli 10, intermediate valves 



