558 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.xxiv. 
slits about 15, lateral slits 2; sinus rather wide, entire; pleural laniinss 
rather wide and short. Lon. of animal about 25; lat. 15; alt. 6 nmi. 
Dredg-ed by the U. S. Fish Commission steamer Albatrom^ at station 
3104-, off the Farallones Islands, in 391 fathoms, coral, bottom tem- 
perature 41- F. U.S.N.M., 109024. 
This species has somewhat the aspect of Trachyraclsia, but presents 
such a mingling" of characters that 1 am in doubt as to which section of 
Ischnochiton would best receive it. 
ISCHNOCHITON SARCOSUS, new species. 
Chiton rather elongate, marbled with scarlet and white, paler mesi- 
ally, rather low and not carinate; the girdle densely set with small, 
curved, smooth bristles of different sizes, dark red and white mixed; 
underside of the girdle chocolate color, and the interior of the valves 
flesh pink; dorsal angle somewhat more than 110*^, the jugal region 
being rounded off; intermediate valves with prominent lateral areas 
hardly concentrically or radially sculptured, but tinelv punctate all over 
and more or less serrate near the girdle on the posterior margin; jugum 
not defined, central area of the valves longitudinalh' sculptured with 
low inosculating wrinkles which sometimes form diamond-shaped inter- 
stitial excavations; the whole sculpture has an obsolete appearance; 
anterior valve finel}^ punctate, feebly concentrically sculptured; pos- 
terior valve the same, with a low subcentralnmcroas in /. m<igdalenen- 
sis; anterior valve with about 8, posterior about 10 slits, intermediate 
valves with 2 slits; sinus wide, entire; pleural lamina?, wide, short; 
lon, in the dry state 36, lat. 15, alt. 5 nnn. 
Dredged in 30 fathoms off San Martin Island, Lower California, by 
Dr. Fred Baker, of San Diego, and also collected at Portuguese Bend, 
near San Pedro, California, by Mr. T. S. Oldroyd. U. S.N.M. , 109043. 
This is an attractive species on account of its fine coloration. It 
would probably go best in Carpenter's section MaiKjereUa^ differing 
ivom. Stenoradsia by the elongate bristly armature of the girdle. 
PELECYPODA. 
LEDA HAMATA Carpenter. 
Plate XL, fig. 9. 
Lcdd hamata Carpenter, Suppl. Rep. Brit. Assoc, 1864, pp. 98, 130; Proc. Cal. 
Acad. Sci., Ill, Feb., 1866, p. 210. 
Near Catalina Island, California, in about 50 fathoms. U.S.N. M., 
107420. 
Shell small, compres.sed, and of a dark chestnut brown. I have' 
figured most of the Ledidce of the present northwest American fauna 
in the Bulletin of the Natural History Society of British Columbia, ' 
and now add to them this interesting but hitherto unfigured species. 
' No. 2, January, 1897. 
