130 



ISCHNOCHITON. 



Chiton coreanicus KEEVE, P. Z. S. 1847, p. 24; Conch. Icon., t. 

 26, f. 128. ADAMS & RVE., Voy. ' Samarang ' Zool.,Moll., t. 15, f. 

 9,ScHRENCK, Reis. u. Forsch. im Arnur-Lande, ii, p. 281, f. 1-6. 

 -Lophyrus coreanicus DKR., Ind. Moll. Mar. Jap., p. 157. 



Carpenter (MS.) compares this to I. pectinulatus and 1. cooperi. 

 Schrenck reports it from the Bay of Hakodadi, on the authority of 

 Lindholm. 

 I. PULCHERRIMUS Sowerby. PL 27, figs. 47, 48. 



Shell oval, elevated; jugum acute; mucro conspicuous, elevated, 

 median, the slope behind it concave. Color red, variously clouded 

 or streaked with ashy. Jugal area hardly defined, smooth at the 

 prominent beaks ; central areas having 16 to 18 acute, subparallel 

 lira? on each side, meeting over the jugum but otherwise nearly 

 parallel; interstices crenulated; entire surface granulated. The 

 interstices are decussated by the buttresses, as it were, of the cren- 

 ulated sides. Lateral areas with 3 principal rows of close knobs, 

 increasing to 5 rows by intercalation. End valves having 16 to 20 

 such rows, the interstices crenulated. Sutures with sharp rows of 

 granules in addition to the contiguous ribs. Interior: anterior 

 valve with 7, central 1, posterior valve 10 slits; teeth obtuse, 

 striated, slightly pectinated ; eaves small ; sinus deep, flat, dentic- 

 ulate. Girdle tessellated; imbricated with large, solid, more or less 

 striated rounded scales. Divergence 97-l 07. (Qpr.) 



Length 24, breadth 13 mill. 



Island o/Bohol, Philippines. 



Chiton pulcherrimus SOWB., P. Z. S. 1841, p. 103. REEVE, 

 Conch. Icon., t. 20, f. 132. 



This species, says Carpenter, is very close to I. mertensii. The 

 striation of the scales is conspicuous in some specimens, on others 

 scarcely seen, yet they all appear conspecific. The species is exactly 

 intermediate between the two genera, Chiton and Ischnochiton, the 

 teeth being scarcely pectinate enough for Chiton, and yet it has the 

 balance of its characters. One specimen has very little light, 

 clouded with dark ; one almost entirely light, with one dark streak 

 on both sides of the central areas; other specimens are inter- 

 mediate. ( Qpr.) 

 I. CRATICULATUS Gould. Unfigured. 



Mucro central, scarcely elevated ; central areas having 18-22 

 bars; on the acute, much elevated jugum scarcely obsolete; 



