120 ISCHNOCHITON. 



under a lens it is seen to be very minutely punctulate, the indistinct 

 lateral areas being obsoletely radiately lirate also. Dark reddish, 

 mottled \vith light on the dorsal ridge. 



The lateral areas are scarcely perceptibly raised and besides being 

 microscopically punctulate like the rest of the surface they have low 

 radiating ribs, about 6 or 7 in number. Central areas evenly 

 punctulate ; end valves punctulate and radiately multilirate. 

 Umbo of posterior valve in front of the middle, rather elevated. 

 Inside: posterior valve with 12, anterior valve 10, median valves 

 1 slit; teeth acute, eaves moderate; sinus wide, flat. 



Girdle densely covered with small, suboval, delicately striated 

 scales. Length 15, breadth 8 mill.; divergence 110. 



SitJca Harbor south to Monterey and the Santa Barbara Is., Cali- 

 fornia. 



Chiton interstinctus OLD., Proc. Bost. Soc. Bost. N. H. ii, p. 145 ; 

 Moll. U. S. Expl. Exped., p. 315, pi. 23, f. 423 ; Otia, p. 230, 242. 

 Ischnochiton interstinctus CPR., MS. 1891, and DALL, Proc. U. S. 

 Nat. Mus. 1878, p. 331. 



This is a small reddish species, characterized by the fine puncta- 

 tion of the whole surface and the rather coarse but low radiating 

 riblets of the lateral areas and end valves. The sculpture is not 

 well shown in Gould's figures. It is drawn from a specimen before 

 me in fig. 39 of pi. 21, representing an enlarged half-valve. 



I. NEWCOMBI Carpenter, n. sp. Unfigured. 



Shell small, wide, tumid, with obtuse rounded jugum. Mucro 

 median, rather elevated. Ashy or olivaceous, elegantly clouded ; 

 central areas and entire surface granulated, the granules being 

 quincuncially arranged, close and regular; lateral areas scarcely 

 defined, having about 4 lines of tubercles which are hardly elevated. 

 Posterior valve having about 30, anterior valve 40 such lines. Inte- 

 rior : posterior valve having 12, median 1, anterior valve 11 slits ; teeth 

 acute ; eaves apparent ; sinus wide, short, scarcely laminate. Girdle 

 imbricated with large striated and rather regular scales. Length 

 81, breadth 61 mill.; divergence 100. (Cpr.) 



Sta. Catalina Is. (Newc.). 



The plan of sculpture somewhat resembles that of I. interstinctus, 

 though coarser and different in detail. It resembles I. radians 

 in most respects except in the rounded beak and larger scales. 

 (Opr.) 



