194 MAZATLA:^ UNIVALVES 



GENUS LEPIDOPLEUEIJS, Eisso. 



H. $ A. Ad. Gen. vol. i. p. 471. Ischnochiton, Grray, Proc. 

 Zool. Soc. 1847, p. 126. Mantle scales very minute, grooved : 

 insertion-plates thin, smooth-edged. 



252. LEPIDOPLEURUS SANGUINEUS, Eve. 



Chiton sanguineus, Eve. Conch. Ic. pi. 17, f. 98. 



Comp. Chiton limaciformis, Sow. Proc. Zool. Soc. 1832, p. 26 : 

 Conch. III. sp. 58, f. 38. Eve. Conch. Ic. pi. 8, sp. 42. (Co- 

 lumbia, Sow. : Inner Lobos Is., Peru, and Guacomayo, under 

 stones at low water, Cuming.) 



This is probably not the Ch. sanguineus of Guilding, from 

 St. Vincent's, which is quoted by Reeve in the Conch. Ic. ; 

 and is certainly not the Ch. sanguineus of Dr. Cutting, from 

 Barbadoes, in the Bristol Museum. It is however identical 

 with the specimens in the Cumingian collection, and most 

 closely resembles Ch. limaciformis. There may be a difference 

 in the integument, which the imperfect state of the specimens 

 has failed to display* The Mazatlan shells are more generally 

 tuberculated on the terminal valves than on the typical speci- 

 mens of the species. 



The mode of attachment is quite different in this shell from 

 that of Lophyrus. The valve margin has an outer and an 

 inner rim ; the outer being a simple continuation of the exter- 

 nal shell layer ; the inner being a white, sharp ridge, cut by 

 10 14 slits in the terminal valves ; so as to give the appear- 

 ance of a lip with a row of incisor teeth within. The central 

 valves have one slit. The radiating punctures are elongated. 

 Inside rose-coloured; outside brownish, pink, or dark olive 

 green, or brown, or yellowish irregularly spotted with green. 

 Surface deeply furrowed with irregular longitudinal lines, 

 waved at the sharply angular diagonal lines. The terminal 

 valves are tuberculose, finely so above, coarselybelow. Interior 

 surface finely corrugated and ridged for the muscular attach- 

 ments. Valve lobes small, arched ; sinus very large. The 

 valves are easily loosened from the membrane, which is 

 generally thin and smooth, sometimes with an irregular whitish 

 deposit, apparently not of organic matter. Long. 1'04, lat. '4, 

 div. 105. 

 Hob. Mazatlan ; very rare ; ISpool Col. 



Tablet 899 contains 4 sp. various colours. 900, 2 sp. opened 

 to shew the valves. 



