34 AMPHINEURA. [Polyplacophora. 



2. Chiton Quoyi, Deshayes, 1836. Plate 2, fig. 13. 



, Chiton Quoyi, Desh., in Lamarck, A.s.V., vii, 509 ; Man. Conch. (1), xiv, 

 172, pi. 37, f. 6-8 ; P. Mai. S., ii, 194. C. viridis, Q. & G., Voy. Astrol., 

 iii, 383, pi. 74, f . 23-28, not of Spengler. C. glaucus, Gray : Hutton, 

 M.N.Z.M., 112. C. Quoyi, Desh. : Wissel, Zool. Jahrb., xx, 620. pi. 2?, 

 f. 33-37 (anatomy). 



Shell oval, rather elevated, carinated, side slopes straight, surface 

 very finely striated, colour usually dark yellowish-green. Anterior 

 valve with numerous narrow, delicate, slightly crenulated, and occasion- 

 ally bifurcated radiating threads. Intermediate valves have the first 

 longer than the succeeding valves, all slightly beaked ; central areas 

 very finely, obliquely longitudinally striated, the striae extending over 

 the jugum ; the lateral areas slightly raised, with radiate riblets 

 similar to those on the head valve. Posterior valve of about the same 

 size as the anterior ; central area with fine longitudinal and posterior 

 with fine radiate threads ; mucro a little in front of the middle, the 

 posterior slope straight. Girdle with smooth, convex, imbricating 

 scales, shining and of about equal size. Colour generally very dark 

 olive-green, but sometimes yellowish-brown marked with olive on the 

 sides and ends, or clear yellow with rays of olive or brown ; uniformly 

 reddish-brown examples occur ; girdle mostly light blue, often with 

 dark-brown scales mingled with the others. Interior light blue, the 

 sutural laminae white ; anterior valve with 9, seldom 10, slits ; median 

 valves with 1 slit on each side ; posterior valve with 13-14 slits ; teeth 

 sharp, minutely pectinate ; sinus very broad, denticulate ; sutural 

 laminae low, rounded ; valve-callus strong, dark green. 



Length, 37 mm. ; breadth, 22 mm. Divergence, 110-120. 

 Dentition. Hutton, T.N.Z.I., xv, 129, pi. 16, f. F. 

 Type. Mus. Hist. Nat., Geneva. 



Hab. Common throughout New Zealand ; under stones between 

 tide-marks. 



Subsp. limosus, Suter, 1905. 



Chiton Quoyi, Desh., sub'sp. limoaus, Suter, J. Mai., xii, 69. Chiton cereus, 

 Reeve : Suter, P. Mai. S., ii, 195, not of Reeve. 



It differs from the species in being smaller and narrower, the ridge 

 generally less acute, colour mostly obscured by a black coating. The 

 anterior valve has only 8 slits, the tail valve 15 ; the sinus is broader ; 

 the sutural laminse slightly higher and much narrower. 



Length, 20 mm. ; breadth, 12 mm. Divergence, 95-100. 

 Type in my collection. 



Hab. Manukau and Auckland Harbours, on mud-flats, under 

 stones between tide-marks ; Lyall Bay. 



