ISCHNOCHITON. 63 



The foot projects forward, concealing the head from beneath. 



I. CONSPICUUS Carpenter, n. sp. PI. 15, figs. 91-96. 



Shell large, elongated, moderately elevated ; green (or rarely 

 earthy-brown), but where eroded at the beaks it is pink. Interior 

 pink, with a blue spot at the jugal sinus. Lateral areas much 

 raised, having acute radiating riblets or striae ; central areas appar- 

 ently smooth, but microscopically granulated, sometimes having some 

 faint longitudinal striae at thejugum. Front slope of the anterior 

 valve concave ; girdle densely beset with short bristles, giving it a vel- 

 vety aspect. 



The entire surface is very densely microscopically granulated, 

 where not eroded. The lateral areas have fine acute radii and 

 often the back edge of each valve is crenulated by oblique, sharp, 

 little folds. The color is often varied by darker little flames on the 

 central areas. The posterior valve is large and depressed. 



The sutural plates are large, the sinus deep and angular. Inser- 

 tion plates having in anterior valve 9, central valves 2 or 3, poste- 

 rior valve 10 slits. Teeth sharp and thin in posterior and central 

 valves, but blunt and bi- or trilobed in anterior valve. Eaves wide, 

 solid, light blue-green colored. 



Length 82, breadth 36 mill. 



Length 89, breadth 41 mill. 



Santa Barbara, California, to Magdalena Bay. 



Maugerella conspicua CPU. MS. OBOUTT, Proc. U. S. Nat. Mus. 

 1885, p. 544. 



This species may be separated from I. acrior by its un sculptured 

 central areas and velvety rather than scaly girdle. It is more 

 closely allied to J. magdalenensis and may, indeed, prove to intergrade 

 with that species ; but in magdalenensis the front valve is scarcely 

 concave in front, the sides of the central areas have a honeycomb 

 sculpture, and the girdle is very finely scaly, not velvety. 



A specimen before me from Magdalena Bay is ferruginous 

 brown, the central areas are more rugose, and the size is smaller, 

 length 45, breadth 20 mill. Another specimen has the central 

 areas sculptured like /. acrior, but less strongly ; the girdle being 

 bristly, however, as in typical conspicuus. San Diego may be 

 regarded as the center of distribution of this species. 



