98 



scars unequal, the right one larger. Lon. of shell 51, lat. 36, alt. 

 13 mm. This shell was received from Dr. L. G. Yates, of Santa 

 Barbara, who obtained it from a dealer at Monterey, Caia., who 

 asserted it to have been obtained alive from the bay of Monterey. 

 Two specimens were obtained, which the possessor would neither 

 lend nor sell; but finally Dr. Yates succeeded in obtaining one of 

 them, which he courteously forwarded to the National Museum 

 for examination. It can only be compared with S. gigas von 

 Martens, of Japan, in which the furrow is obsolete, and there are 

 no secondary ribs, and the primary ribs are feeble, low, wide, 

 and obsolete on the anterior part of the shell. If the locality is 

 confirmed, the species is a notable addition to the Californian 

 fauna." — Dall, Nautilus 14:125. 



1440 Lepidopleurus mesogonus Dall. 



Off Queen Charlotte Islands, B. C, in 1,588 fms. 



1441 Lepidopleurus halistreptus Dall. 

 Type locality:— off Acapulco, Mexico. 



1442 Lepidopleurus luridus Dall. 

 Type locality: — Panama bay. 



1443 Lepidopleurus farallonis Dall. 



Type locality:- — off Farallones Islands, near San Francisco, 

 Cal., in 391 fms. 



Chiton small, thin, wide, with a low rounded back and yellow- 

 ish-white color; girdle narrow, sparsely spiculose, with very short, 

 fine, bristly spicules; jugum hardly defined, with no obvious 

 mucro; lateral areas slightly elevated and feebly concentrically 

 rugose; anterior valve simple; posterior conspicuously mucronate 

 and, behind the mucro, concave; surface entirely covered with 

 minute, low, close-set pustules, arranged quincunciaily and to 

 some extent concentrically from the mucronal points; pleural 

 laruinse short, subtriangular; ctenidial line reaching the fifth 

 valve. Lon. of animal about 10, lat. 5.5, alt. 2 mm. 



1444 Ischnochiton Steamsii Dall. 



Chiton of moderate size, yellowish or buff color; girdle yellow- 

 ish-white, covered with subcylindric, blunt, smooth, close-set, 

 large spines, the ends of which have a pebbly appearance, mixed 

 with a smaller proportion of small but rather similar spicules; 

 ends of large spines, when worn flat, have a pavement-like aspect; 

 back not keeled, but rather steeply rounded; gills ambient; inter- 

 mediate valves with a dorsal angle of about 90 degrees, the lateral 

 areas prominent, with about 5 radial riblets in each, divaricating 

 to 7 or 10 at the girdle margin, and cut into beads by numerous 

 fine concentric furrows; pleural areas and jugum hardly differ- 

 entiated, sculptured with fine, slightly irregular, longitudinal 

 wrinkles, finer mesially, crossed by inconspicuous, less elevated 

 transverse lines; anterior valve with fine, beaded, divaricate radial 

 riblets, the insertion plates and eaves very short, smooth, not 

 spongy, with about 17 slits; the posterior valve with a small, low, 

 subcentral mucro, from which 2 elevated lines extend to the mar- 

 gin, 1 on either side, forming 2 areas, and from which the wrinkled 

 sculpture, less prominent on the anterior area, diverges; posterior 

 slits about 15, lateral slits 2; sinus rather wide, entire; pleural 

 lamina? rather wide and short. Lon. of animal about 25, lat. 

 15, alt. 6 mm. 



Type locality: — off Farallones Islands, near San Francisco, 



