CLASS GASTROPODA 
299 
edged jugal sinus and rather broad sutural laminae. Length, 13; width, 8; 
height, 3 mm. (Dali.) 
Type in United States National Museum, No. 109317. Type locality, 
Long Beach, California. 
Range. Long Beach and San Pedro, California. 
Family CHITONIDAE 
Genus TONICIA Gray, 1847 
Anterior and posterior valves with many slits, middle with one; teeth 
sharp, serrate; eaves short, spongy; sinus squared, denticulate; girdle 
smooth or downy; gills encircling. (Tryon, Structural and Systematic 
Conchology .) 
Type. C. elegans Fremb. 
Distribution. Western America, West Indies, New Zealand, Aus¬ 
tralia, Red Sea, Philippines. 
Tonicia pustulifera Dali, 1919 
Proceedings of the United States National Museum, 55:516. 
Chiton of moderate size, polished, yellowish mottled with dark green, 
dark brown, and brown dots, the back rounded, the girdle yellowish, 
densely covered with minute short spinules giving a velvety aspect and 
with no fringe of longer spines at the border; anterior valve with 8, 
posterior with 11, intermediate valves with single slits, the insertion plates 
minutely radially striated; anterior valve more than semicircular with a 
profusion of minute pustules corresponding to sense organs and leaving 
a puncture when worn off; otherwise smooth; posterior valve smaller with 
the mucro much in front of the center, the central area narrow, sculpture 
as in the anterior valve, internally with a pink spot, the jugal sinus small 
and shallow, the sutural laminae long and narrow; intermediate valves 
with the first axially longer than the others, the valves slightly mucronate, 
the jugal area narrow and smooth except on the first valve which has a 
few axial grooves, the pleural tracts smooth except for a few very feeble 
wavy subaxial threads often obsolete on one side of the same valve, 
stronger near the jugum and on the posterior valves, and a few scattered 
very minute pustules; there are faint traces in spots, of a microscopic 
decussation; lateral areas without ribs, feebly indicated, bearing oblique 
rows of minute pustules; internally white, pinkish under the jugum, the 
jugal sinus narrow, deep, straight-edged, the sutural laminae broad, arcu- 
[901] 
