78 ISCHNOCHITON. 



Interior: anterior and posterior valves having 7 slits, median 

 valves 1 slit ; teeth a little acute, eaves large, pectinated by the 

 tubercles or little bubbles of the outer surface ; sinus moderate, 

 deep, flat, smooth. 



Girdle closely beset with rather flat, subpilose, minute scales. 



Length 15, breadth 7* mill. ; div. 95. 



Habitat unknown. 



f Trachydermon perornatus CPU., MS. p. 19. 



Congeneric with asperior, but easily distinguished by the very 

 strong sculpture, flattened mucro, yet sharp elevation of the shell. 



I. VIRGATUS Reeve. PL 8, figs. 72, 73 (enlarged). 



Shell oblong-ovate, minute ; valves smooth, or under a lens very 

 finely reticulated ; beautifully mottled and striped with bluish- 

 green and yellow. Ligament very minutely scaly, marbled. (Rye.*) 



Port Lincoln, Australia. 



Ch. virgatus Rv., Conch. Icon. t. 28, f. 192, 1848. Trachydermon 

 virgatus Rv., CARPENTER, MS. p. 22. Ischnochiton virgatus Rv., 

 CPR., MS. p. 106. 



Carpenter writes as follows of the type specimens : Two speci- 

 mens, Mus. Cuming ; minute, length 5, breadth 2 mill. ; div. 85. 

 Shell very arched, the jugum rather obtuse but not very. Mucro 

 elevated, the posterior slope slightly concave. It looks externally 

 like the young of lentiginosus, being painted in the same way- 

 olivaceous with bluish-green spots. Girdle tessellated with very 

 small scales, not striated; granular. The three areas are scarcely 

 to be distinguished. Very conspicuously quasi-granulate all over. 

 The jugular part is partially streaked with brown in one specimen, 

 blotched with ashen in the other. The anterior valve has 9, central 

 valves 1, posterior valve 9 slits. Teeth sharp, few, long. Eaves 

 moderate. Sinus broad, moderate, flat, not channelled. 



I. VIRESCENS Reeve. PL 8, figs. 74, 75. 



Shell ovate, valves smooth, crenulated along the posterior edge ; 

 bright pale green ; ligament horny. (Ev.) 



Habitat unknown. 



Chiton virescens REEVE, Conch. Icon. t. 20, f. 126, May, 1847. 

 "/ f Trachydermon virescens " CPR., MS. p. 21. 



