ISCHNOCHITON. 117 



I. COMPTUS Gould. 



Shell 'small, thin, elliptical ; green or scarlet, frequently banded, 

 dotted or maculated with whitish or yellow. Valves short, the end 

 valves radiately ribbed and punctate; central areas quincuncially 

 punctate. Lateral areas elevated and sculptured with 4-5 radia- 

 ting grooves. Interior green. Girdle narrow, imbricated with 

 small elongated grooved scales. Length 15, diam. 10 mill. (Old.} 

 Oosima, Japan ; Bonin and Liu-Kiu Is. (Stimpson). 



C. (Leptochiton) comptus GOULD, Proc. Bost. Soc. N. H. vii, p. 

 163 ; Otia, p. 117. Isch. comptus CPR., MS. 



Carpenter writes : Entire surface punctate ; central areas having 

 the lines of points either parallel or bending toward the acute 

 jugum ; lateral areas having small radiating wrinkles, at first 3 to 4 

 in number, then splitting into 6 to 8. End valves having 40 deli- 

 cate, hardly apparent radiating wrinkles. Mucro slightly in front 

 of the middle, slightly elevated. Interior: posterior valve with 

 13, central valve 1, anterior valve 14 slits; teeth acute; eaves 

 moderate, acute ; sinus wide, flat. Girdle having large, solid 

 imbricating scales, sometimes very slightly striated. Length 17i, 

 breadth 10 mill. ; divergence 120. Philippines, Mus. Cuming No. 



II. Dr. Gould strangely placed this species in Leptochiton, 

 although the scales are as large, solid and regular as in Chiton. 

 The above diagnosis is written from Mr. Cuming's beautiful speci- 

 mens, which are broad and externally curiously like the young of 

 Chiton, (var.) patulus: In the typical specimens, the stimulation of 

 the scales can seldom be seen, having apparently lived in exposed 

 situations. The variation in color is extraordinary, being (a) 

 densely clouded with olive; (6) light ditto mottled with dark and 

 lilac; (c) four central valves chestnut, the rest olivaceous; (d) 

 brown with olive, with broad white streak down the centre ; (e) 

 light reddish-chestnut mottled ; (/) ditto, shading into olivaceous ; 

 (g) sixth, seventh and part of eighth valve dark olive-brown, the 

 rest light ashy ; (A) the whole light ash. The sutures are always 

 regularly spotted, as in T. pseudodentiens. In the typical specimen 

 examined there were only eleven slits in the terminal valves. 



I. LEPIDUS Gould. Unfigured. 



Shell small, elliptical, roof-shaped, yellow-green streaked with 

 olive ; front valve semi-circular, radially striated ; posterior valve 

 crescentric, beaked, radially grooved behind and longitudinally in 



